scripts: do not use uninitialized variable

A previous commit removed the 'ret' variable when
switching to subprocess.run, but did not adjust
the exit code.

Fixes: 15c9ca383c
Signed-off-by: Ján Tomko <jtomko@redhat.com>

scripts/check-file-access.py

@@ -42,7 +42,7 @@ proc = subprocess.run(sys.argv[1:])
 if proc.returncode != 0 or os.read(access_fd, 10) == b'':
     os.close(access_fd)
     os.remove(access_file)
-    sys.exit(ret)
+    sys.exit(proc.returncode)
 
 known_actions = ["open", "fopen", "access", "stat", "lstat", "connect"]