Fix factory test

client/common_lib/gbb_util.py

 #!/usr/bin/env python
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Provides convenience routines to access the GBB on the current BIOS.
 
    GBBUtility is a wrapper of gbb_utility program.
 """
 
@@ skipping 11 matching lines @@
     It accesses the GBB on the current BIOS image.
     """
     def __init__(self,
                  gbb_command='gbb_utility',
                  temp_dir=None,
                  keep_temp_files=False):
         self._gbb_command = gbb_command
         self._temp_dir = temp_dir
         self._keep_temp_files = keep_temp_files
         self._need_commit = False
+        self._gbb_file = None
         self._clear_cached()
 
 
     def __del__(self):
         if self._gbb_file:
             self._remove_temp_file(self._gbb_file)
         if self._need_commit:
             raise error.TestError(
                 'You changed somethings; should commit or discard them.')
 
@@ skipping 141 matching lines @@
                 self._remove_temp_file(rootkey_file)
             self._need_commit = False
             self._clear_cached()
 
 
     def discard(self):
         """Discard all uncommitted changes."""
         if self._need_commit:
             self._need_commit = False
             self._clear_cached()