message: Avoid double-destructor in ScopedTfFunction
diff: @@ -88,7 +88,9 @@ class ScopedTFFunction(object):
  # Note: when we're destructing the global context (i.e when the process is
  # terminating) we can have already deleted other modules.
  if c_api is not None and c_api.TF_DeleteFunction is not None:
  + if self.func is not None:
  c_api.TF_DeleteFunction(self.func)
  + self.func = None
  class ApiDefMap(object):
  