fix format

Signed-off-by: Mu Huai <tianbowen.tbw@antgroup.com>

Author: Mu Huai

vllm/v1/engine/output_processor.py

@@ -405,7 +405,9 @@ def process_outputs(
     def do_tracing(self, engine_core_output: EngineCoreOutput,
                    req_state: RequestState,
                    iteration_stats: Optional[IterationStats]):
-        if engine_core_output.finish_reason is None or iteration_stats is None or req_state is None or req_state.stats is None or self.tracer is None:
+        if (engine_core_output.finish_reason is None
+                or iteration_stats is None or req_state is None
+                or req_state.stats is None or self.tracer is None):
             return
         arrival_time_nano_seconds = int(req_state.stats.arrival_time * 1e9)