Update adversarial_regularization.py

Author: wangbingnan136

neural_structured_learning/keras/adversarial_regularization.py

@@ -743,7 +743,7 @@ def save(self,
     ```
     """
     # pylint: enable=line-too-long
-    save.save_model(self, filepath, overwrite, include_optimizer, save_format,
+    save.save_model(self.base_model, filepath, overwrite, include_optimizer, save_format,
                     signatures, options, save_traces)