message: Fix the error message thrown when running eval on pod
diff: @@ -599,8 +599,8 @@ class _InternalTPUContext(object):
  .format(self._eval_batch_size, num_replicas))
  if num_hosts > 1 and not self.is_input_broadcast_with_iterators():
  raise ValueError(
  - 'TPUEstimator.evaluate should be running on single TPU worker. '
  - 'got {}.'.format(num_hosts))
  + 'TPUEstimator.evaluate should be running on single TPU'
  + ' instead of a Pod.')
  else:
  assert mode == model_fn_lib.ModeKeys.PREDICT
  if self._predict_batch_size is None:
  