message: update ragged_string_ops.py comment
diff: @@ -457,8 +457,8 @@ def string_split_v2(input, sep=None, maxsplit=-1, name=None): # pylint: disable
  """Split elements of `input` based on `sep` into a `RaggedTensor`.
  Let N be the size of `input` (typically N will be the batch size). Split each
  - element of `input` based on `sep` and return a `SparseTensor` or
  - `RaggedTensor` containing the split tokens. Empty tokens are ignored.
  + element of `input` based on `sep` and return a `RaggedTensor` containing the
  + split tokens. Empty tokens are ignored.
  Example:
  