message: Update doc examples for tf.Variable.{scatter_nd_add,scatter_nd_sub}
diff: @@ -817,14 +817,13 @@ class Variable(six.with_metaclass(VariableMetaclass, trackable.Trackable)):
  v = tf.Variable([1, 2, 3, 4, 5, 6, 7, 8])
  indices = tf.constant([[4], [3], [1] ,[7]])
  updates = tf.constant([9, 10, 11, 12])
  - op = v.scatter_nd_sub(indices, updates)
  - with tf.compat.v1.Session() as sess:
  - print sess.run(op)
  + v.scatter_nd_sub(indices, updates)
  + print(v)
  ```
  - The resulting update to v would look like this:
  + After the update `v` would look like this:
  - [1, -9, 3, -6, -6, 6, 7, -4]
  + [1, -9, 3, -6, -4, 6, 7, -4]
  See `tf.scatter_nd` for more details about how to make updates to
  slices.
  @@ -864,9 +863,8 @@ class Variable(six.with_metaclass(VariableMetaclass, trackable.Trackable)):
  v = tf.Variable([1, 2, 3, 4, 5, 6, 7, 8])
  indices = tf.constant([[4], [3], [1] ,[7]])
  updates = tf.constant([9, 10, 11, 12])
  - add = v.scatter_nd_add(indices, updates)
  - with tf.compat.v1.Session() as sess:
  - print sess.run(add)
  + v.scatter_nd_add(indices, updates)
  + print(v)
  ```
  The resulting update to v would look like this:
  