Fix typo in tokenization_chatglm.py

tokenization_chatglm.py

@@ -299,7 +299,7 @@ class ChatGLMTokenizer(PreTrainedTokenizer):
         """
         if os.path.isdir(save_directory):
             vocab_file = os.path.join(
-                save_directory, VOCAB_FILES_NAMES["vocab_file"]
+                save_directory, self.vocab_files_names["vocab_file"]
             )
         else:
             vocab_file = save_directory