Fix warnings in pkg_editor

[pcolberg]

Warnings from Ubuntu 22.04 debug build with GCC 11.2:

• lib/pkg_editor/src/pkg_editor.c

  [84/113] /usr/bin/gcc -DNOMINMAX -DUSE_ZLIB -I/__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/include -g -fPIC -Wall -Wconversion -Wformat -Wformat-security -fno-strict-aliasing -fstack-protector -D_FORTIFY_SOURCE=2 -Og -MD -MT lib/pkg_editor/CMakeFiles/pkg_editor.dir/src/pkg_editor.c.o -MF lib/pkg_editor/CMakeFiles/pkg_editor.dir/src/pkg_editor.c.o.d -o lib/pkg_editor/CMakeFiles/pkg_editor.dir/src/pkg_editor.c.o -c /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'make_string_table_extensible':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:165:16: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'Elf32_Word' {aka 'unsigned int'} may change value [-Wconversion]
    165 |     return data->d_size;
        |            ~~~~^~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:184:14: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'Elf32_Word' {aka 'unsigned int'} may change value [-Wconversion]
    184 |   return data->d_size;
        |          ~~~~^~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'acl_pkg_read_file_into_buffer':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:466:15: warning: conversion to 'size_t' {aka 'long unsigned int'} from 'long int' may change the sign of the result [-Wsign-conversion]
    466 |   file_size = ftell(f);
        |               ^~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'set_shdrstrndx':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:784:29: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'Elf32_Word' {aka 'unsigned int'} may change value [-Wconversion]
    784 |     scn_zero_hdr->sh_link = shdrstrndx;
        |                             ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:790:24: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'Elf32_Half' {aka 'short unsigned int'} may change value [-Wconversion]
    790 |     ehdr->e_shstrndx = shdrstrndx;
        |                        ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'acl_pkg_open_file':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:976:24: warning: conversion from 'int' to 'unsigned char:1' may change value [-Wconversion]
    976 |   result->show_error = show_error;
        |                        ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:977:23: warning: conversion from 'int' to 'unsigned char:1' may change value [-Wconversion]
    977 |   result->show_info = show_info;
        |                       ^~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'acl_pkg_open_file_from_memory':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1044:23: warning: conversion from 'int' to 'unsigned char:1' may change value [-Wconversion]
   1044 |   result->show_info = show_info;
        |                       ^~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1045:24: warning: conversion from 'int' to 'unsigned char:1' may change value [-Wconversion]
   1045 |   result->show_error = show_error;
        |                        ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'acl_pkg_set_show_mode':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1099:22: warning: conversion from 'int' to 'unsigned char:1' may change value [-Wconversion]
   1099 |     pkg->show_info = show_info;
        |                      ^~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1100:23: warning: conversion from 'int' to 'unsigned char:1' may change value [-Wconversion]
   1100 |     pkg->show_error = show_error;
        |                       ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'append_data':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1120:27: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'uInt' {aka 'unsigned int'} may change value [-Wconversion]
   1120 |   z_info->strm.avail_in = size;
        |                           ^~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'add_file':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:58:20: warning: signed conversion from 'unsigned int' to 'int' changes value from '3203399403' to '-1091567893' [-Wsign-conversion]
     58 | #define PACK_MAGIC 0xBEEFFEEB
        |                    ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1178:16: note: in expansion of macro 'PACK_MAGIC'
   1178 |   info.magic = PACK_MAGIC;
        |                ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1180:20: warning: conversion to 'int' from 'unsigned int' may change the sign of the result [-Wsign-conversion]
   1180 |   info.file_mode = mode;
        |                    ^~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1181:22: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'unsigned int' may change value [-Wconversion]
   1181 |   info.name_length = name_length;
        |                      ^~~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'add_directory':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:58:20: warning: signed conversion from 'unsigned int' to 'int' changes value from '3203399403' to '-1091567893' [-Wsign-conversion]
     58 | #define PACK_MAGIC 0xBEEFFEEB
        |                    ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1257:16: note: in expansion of macro 'PACK_MAGIC'
   1257 |   info.magic = PACK_MAGIC;
        |                ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1260:22: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'unsigned int' may change value [-Wconversion]
   1260 |   info.name_length = name_length;
        |                      ^~~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'add_file_or_dir':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1394:64: warning: conversion from '__off_t' {aka 'long int'} to 'unsigned int' may change value [-Wconversion]
   1394 |     return add_file(out_file, of, file_or_dir, buf.st_mode, buf.st_size,
        |                                                             ~~~^~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'acl_pkg_pack':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:58:20: warning: signed conversion from 'unsigned int' to 'int' changes value from '3203399403' to '-1091567893' [-Wsign-conversion]
     58 | #define PACK_MAGIC 0xBEEFFEEB
        |                    ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1446:16: note: in expansion of macro 'PACK_MAGIC'
   1446 |   info.magic = PACK_MAGIC;
        |                ^~~~~~~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'read_data':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1462:28: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'uInt' {aka 'unsigned int'} may change value [-Wconversion]
   1462 |   z_info->strm.avail_out = size;
        |                            ^~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1472:15: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   1472 |       count = fread(z_info->buffer, 1, sizeof(z_info->buffer), in_fd);
        |               ^~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1477:31: warning: conversion to 'uInt' {aka 'unsigned int'} from 'int' may change the sign of the result [-Wsign-conversion]
   1477 |       z_info->strm.avail_in = count;
        |                               ^~~~~
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c: In function 'acl_pkg_unpack_buffer_or_file':
  /__w/fpga-runtime-for-opencl/fpga-runtime-for-opencl/lib/pkg_editor/src/pkg_editor.c:1532:28: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'uInt' {aka 'unsigned int'} may change value [-Wconversion]
   1532 |     z_info.strm.avail_in = buffer_size;
        |                            ^~~~~~~~~~~