clang/scripts/package.py: return exit code 0, when nothing to do.

tools/clang/scripts/package.py

 #!/usr/bin/env python
 # Copyright (c) 2015 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.
 
 """This script will check out llvm and clang, and then package the results up
 to a tgz file."""
 
 import argparse
 import fnmatch
@@ skipping 132 matching lines @@
 
   # Check if Google Cloud Storage already has the artifacts we want to build.
   if (args.upload and GsutilArchiveExists(pdir, platform) and
       not sys.platform.startswith('linux') or
       GsutilArchiveExists(golddir, platform)):
     print ('Desired toolchain revision %s is already available '
            'in Google Cloud Storage:') % expected_stamp
     print 'gs://chromium-browser-clang/%s/%s.tgz' % (platform, pdir)
     if sys.platform.startswith('linux'):
       print 'gs://chromium-browser-clang/%s/%s.tgz' % (platform, golddir)
-    return 1
+    return 0
 
   with open('buildlog.txt', 'w') as log:
     Tee('Diff in llvm:\n', log)
     TeeCmd(['svn', 'stat', LLVM_DIR], log, fail_hard=False)
     TeeCmd(['svn', 'diff', LLVM_DIR], log, fail_hard=False)
     Tee('Diff in llvm/tools/clang:\n', log)
     TeeCmd(['svn', 'stat', os.path.join(LLVM_DIR, 'tools', 'clang')],
            log, fail_hard=False)
     TeeCmd(['svn', 'diff', os.path.join(LLVM_DIR, 'tools', 'clang')],
            log, fail_hard=False)
@@ skipping 124 matching lines @@
     with tarfile.open(golddir + '.tgz', 'w:gz') as tar:
       tar.add(os.path.join(golddir, 'lib'), arcname='lib',
               filter=PrintTarProgress)
     MaybeUpload(args, golddir, platform)
 
   # FIXME: Warn if the file already exists on the server.
 
 
 if __name__ == '__main__':
   sys.exit(main())