message: Fix ResourceVariable's docstring example.
diff: @@ -184,11 +184,12 @@ class ResourceVariable(variables.Variable):
  assign = a.assign(2.0)
  with tf.control_dependencies([assign]):
  b = a.read_value()
  -
  + with tf.control_dependencies([b]):
  other_assign = a.assign(3.0)
  with tf.control_dependencies([other_assign]):
  - tf.Print(b, [b]).run() # Will print 2.0 because the value was read before
  - # other_assign ran.
  + # Will print 2.0 because the value was read before other_assign ran. If
  + # `a` was a tf.Variable instead, 2.0 or 3.0 could be printed.
  + tf.Print(b, [b]).eval()
  ```
  To enforce these consistency properties tf.ResourceVariable might make more
  