[https://nvbugs/5753250][fix] Fix undefined local variable in responses utils

Signed-off-by: Junyi Xu <[email protected]>

Author: JunyiXu-nv

tensorrt_llm/serve/responses_utils.py

@@ -973,6 +973,7 @@ async def _create_output_content(
     available_tools = _get_chat_completion_function_tools(tools)
 
     for output in final_res.outputs:
+        calls = []
         text, reasoning_text = _apply_reasoning_parser(reasoning_parser,
                                                        output.index,
                                                        output.text, False)