message: Fix logging format error in retrain.py
  This fix fixes the logging format error in
  `tensorflow/examples/image_retraining/retrain.py`.
  This fix fixes 16735.
diff: @@ -344,8 +344,8 @@ def maybe_download_and_extract(data_url):
  filepath, _ = urllib.request.urlretrieve(data_url, filepath, _progress)
  print()
  statinfo = os.stat(filepath)
  - tf.logging.info('Successfully downloaded', filename, statinfo.st_size,
  - 'bytes.')
  + tf.logging.info('Successfully downloaded %s %d bytes.',
  + filename, statinfo.st_size)
  print('Extracting file from ', filepath)
  tarfile.open(filepath, 'r:gz').extractall(dest_directory)
  else:
  