fix pylint warnings

native_client_sdk/src/build_tools/build_sdk.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Entry point for both build and try bots
 
 This script is invoked from XXX, usually without arguments
 to package an SDK. It automatically determines whether
 this SDK is for mac, win, linux.
 
 The script inspects the following environment variables:
 
 BUILDBOT_BUILDERNAME to determine whether the script is run locally
 and whether it should upload an SDK to file storage (GSTORE)
 """
 
+# pylint: disable=W0621
 
 # std python includes
 import copy
 import datetime
 import generate_make
 import optparse
 import os
 import platform
 import subprocess
 import sys
@@ skipping 803 matching lines @@
       # Archive on non-trybots.
       if options.archive or buildbot_common.IsSDKBuilder():
         BuildStepArchiveBundle(pepper_ver, clnumber, tarfile)
         BuildStepArchiveSDKTools()
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))