Move xtrace early

I dug back through the history to see why xtrace is enabled where it
is.  Originally (like first commit originally), it was somewhat sanely
placed to turn on tracing after it had done the interactive
"read_password" prompt stuff.  Over time, it has just shuffled it's
way down as stuff got added around it.

This was noticed this because I was looking for tracing of earlier
commands when looking at the repo setup (see
Iec2ad7b5598fdaefbc2338ade702bc7b08963b96) and couldn't find it.

Putting this at the start means we both capture all output
unconditionally, and avoid needlessly getting this interleaved at some
odd place again.

Change-Id: I441d7eecbab9d204258c18a071ccc1cbf4f7512a

Author: ianw

stack.sh

@@ -21,6 +21,10 @@
 
 # Learn more and get the most recent version at http://devstack.org
 
+# Print the commands being run so that we can see the command that triggers
+# an error.  It is also useful for following along as the install occurs.
+set -o xtrace
+
 # Make sure custom grep options don't get in the way
 unset GREP_OPTIONS
 
@@ -485,10 +489,6 @@ function err_trap {
 # Begin trapping error exit codes
 set -o errexit
 
-# Print the commands being run so that we can see the command that triggers
-# an error.  It is also useful for following along as the install occurs.
-set -o xtrace
-
 # Print the kernel version
 uname -a