intel/tools/aubinator_error_decode: exit with an error on unknown option

Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7833>

src/intel/tools/aubinator_error_decode.c

@@ -783,6 +783,9 @@ main(int argc, char *argv[])
       case 'x':
          xml_path = strdup(optarg);
          break;
+      case '?':
+         print_help(argv[0], stderr);
+         exit(EXIT_FAILURE);
       default:
          break;
       }