perf python: Set index error for invalid thread/cpu map items

JIRA: https://issues.redhat.com/browse/RHEL-78198

upstream
========
commit b4aff7e
Author: Ian Rogers <irogers@google.com>
Date: Thu Jul 10 16:51:26 2025 -0700

description
===========
Returning NULL for out of bound CPU or thread map items causes
internal errors. Fix by correctly setting the error to be an index
error.

    Signed-off-by: Ian Rogers <irogers@google.com>
    Link: https://lore.kernel.org/r/20250710235126.1086011-14-irogers@google.com
    Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Signed-off-by: Michael Petlan <mpetlan@redhat.com>

Author: rfmvh

tools/perf/util/python.c

@@ -529,8 +529,10 @@ static PyObject *pyrf_cpu_map__item(PyObject *obj, Py_ssize_t i)
 {
 	struct pyrf_cpu_map *pcpus = (void *)obj;
 
-	if (i >= perf_cpu_map__nr(pcpus->cpus))
+	if (i >= perf_cpu_map__nr(pcpus->cpus)) {
+		PyErr_SetString(PyExc_IndexError, "Index out of range");
 		return NULL;
+	}
 
 	return Py_BuildValue("i", perf_cpu_map__cpu(pcpus->cpus, i).cpu);
 }
@@ -598,8 +600,10 @@ static PyObject *pyrf_thread_map__item(PyObject *obj, Py_ssize_t i)
 {
 	struct pyrf_thread_map *pthreads = (void *)obj;
 
-	if (i >= perf_thread_map__nr(pthreads->threads))
+	if (i >= perf_thread_map__nr(pthreads->threads)) {
+		PyErr_SetString(PyExc_IndexError, "Index out of range");
 		return NULL;
+	}
 
 	return Py_BuildValue("i", perf_thread_map__pid(pthreads->threads, i));
 }