Update openclaw_hf/backup.py

openclaw_hf/backup.py

@@ -2456,7 +2456,7 @@ class OpenClawBackup:
                     fcntl.flock(lock_fd, fcntl.LOCK_UN)
                 except (OSError, IOError):
                     pass
-                lock_fd.close()
+                os.close(lock_fd)
 
             try:
                 lock_path.unlink(missing_ok=True)