[3.13] gh-130052: Fix search_map_for_section() error handling (GH-132594) (#132598)

gh-130052: Fix search_map_for_section() error handling (GH-132594)

* Don't call close() if the file descriptor is negative.
* If close() fails, chain the existing exception.
(cherry picked from commit 014c7f9047)

Co-authored-by: Victor Stinner <vstinner@python.org>

Modules/_testexternalinspection.c

@@ -345,8 +345,10 @@ get_py_runtime_linux(pid_t pid)
     }
 
 exit:
-    if (close(fd) != 0) {
+    if (fd >= 0 && close(fd) != 0) {
+        PyObject *exc = PyErr_GetRaisedException();
         PyErr_SetFromErrno(PyExc_OSError);
+        _PyErr_ChainExceptions1(exc);
     }
     if (file_memory != NULL) {
         munmap(file_memory, file_stats.st_size);