message: Fix softmax_cross_entropy issue
  This fix is from 24397/24736 and all credit goes to
  This fix fixes 24397. This fix fixes 24736.
diff: @@ -794,7 +794,7 @@ def softmax_cross_entropy(
  if label_smoothing > 0:
  num_classes = math_ops.cast(
  - array_ops.shape(onehot_labels)[1], logits.dtype)
  + array_ops.shape(onehot_labels)[-1], logits.dtype)
  smooth_positives = 1.0 - label_smoothing
  smooth_negatives = label_smoothing / num_classes
  onehot_labels = onehot_labels * smooth_positives + smooth_negatives
  