message: Fix comments to match usage
  Fix comments of `sparse_softmax_cross_entropy_with_logits` to match usage.
diff: @@ -1980,8 +1980,9 @@ def sparse_softmax_cross_entropy_with_logits(
  on `logits` internally for efficiency. Do not call this op with the
  output of `softmax`, as it will produce incorrect results.
  - A common use case is to have logits and labels of shape
  - `[batch_size, num_classes]`, but higher dimensions are supported, in which
  + A common use case is to have logits of shape
  + `[batch_size, num_classes]` and have labels of shape
  + `[batch_size]`, but higher dimensions are supported, in which
  case the `dim`-th dimension is assumed to be of size `num_classes`.
  `logits` must have the dtype of `float16`, `float32`, or `float64`, and
  `labels` must have the dtype of `int32` or `int64`.
  