Fix log message in scheduler (#652)

Author: LiuXiaoxuanPKU

vllm/core/scheduler.py

@@ -190,13 +190,13 @@ def _schedule(
                     break
 
                 num_prompt_tokens = seq_group.get_seqs()[0].get_len()
-                if num_prompt_tokens > min(
-                        self.scheduler_config.max_model_len,
-                        self.scheduler_config.max_num_batched_tokens):
+                prompt_limit = min(
+                    self.scheduler_config.max_model_len,
+                    self.scheduler_config.max_num_batched_tokens)
+                if num_prompt_tokens > prompt_limit:
                     logger.warning(
                         f"Input prompt ({num_prompt_tokens} tokens) is too long"
-                        " and exceeds limit of "
-                        f"{self.scheduler_config.max_model_len}")
+                        f" and exceeds limit of {prompt_limit}")
                     for seq in seq_group.get_seqs():
                         seq.status = SequenceStatus.FINISHED_IGNORED
                     ignored_seq_groups.append(seq_group)