Fix typo in merge_pgc_files.py

build/win/merge_pgc_files.py

 #!/usr/bin/env python
 # Copyright 2017 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.
 
 """Merge the PGC files generated during the profiling step to the PGD database.
 
 This is required to workaround a flakyness in pgomgr.exe where it can run out
 of address space while trying to merge all the PGC files at the same time.
 """
@@ skipping 112 matching lines @@
           os.path.join(options.build_dir, os.path.basename(pgc_file)))
     ret = merge_pgc_files(pgomgr_path, files_to_merge, pgd_file)
     # pgomgr.exe sometimes fails to merge too many files at the same time (it
     # usually complains that a stream is missing, but if you try to merge this
     # file individually it works), try to merge all the PGCs from this batch one
     # at a time instead. Don't fail the build if we can't merge a file.
     # TODO(sebmarchand): Report this to Microsoft, check if this is still
     # happening with VS2017.
     if ret != 0:
       print ('Error while trying to merge several PGC files at the same time, '
-             'trying to merge them one by one.'
+             'trying to merge them one by one.')
       for pgc_file in chunk:
         ret = merge_pgc_files(
             pgomgr_path,
             [os.path.join(options.build_dir, os.path.basename(pgc_file))],
             pgd_file
         )
         if ret != 0:
           print 'Error while trying to merge %s, continuing.' % pgc_file
 
 
 if __name__ == '__main__':
   sys.exit(main())