Fix close/unlink order for file locking.
Reviewed in https://codereview.appspot.com/7313056/.
diff --git a/oauth2client/locked_file.py b/oauth2client/locked_file.py
index 313d0c5..26f783e 100644
--- a/oauth2client/locked_file.py
+++ b/oauth2client/locked_file.py
@@ -142,8 +142,8 @@
     """Unlock a file by removing the .lock file, and close the handle."""
     if self._locked:
       lock_filename = self._posix_lockfile(self._filename)
-      os.unlink(lock_filename)
       os.close(self._lock_fd)
+      os.unlink(lock_filename)
       self._locked = False
       self._lock_fd = None
     if self._fh: