WebRTC: Fix syntax error in cleanup_symlinks.py.

scripts/slave/recipe_modules/webrtc/resources/cleanup_symlinks.py

 #!/usr/bin/env python
 # Copyright 2016 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.
 
 """Script that deletes all symlinks created by setup_links.py in a checkout."""
 
 import os
 import subprocess
 import sys
 
 
 def main(args):
   if len(args) != 1:
     print >> sys.stderr, ('Please specify a single directory as an argument, '
-                          'which points to the checkout root (dir above src/).'
+                          'which points to the checkout root (dir above src/).')
     return 1
 
   checkout_root = args[0]
   if not os.path.isdir(checkout_root):
     print 'Cannot find any directory at %s. Skipping cleaning.' % checkout_root
     return 0
 
   setup_links_file = os.path.join(checkout_root, 'src', 'setup_links.py')
   if os.path.isfile(setup_links_file):
     print 'Cleaning up symlinks in %s' % checkout_root
     subprocess.check_call([sys.executable, setup_links_file, '--clean-only'],
                           cwd=checkout_root)
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))