[Bugfix] Fix a log error in chunked prefill (#6694)

Author: WoosukKwon

vllm/config.py

@@ -814,7 +814,7 @@ def __init__(self,
         if enable_chunked_prefill:
             logger.info(
                 "Chunked prefill is enabled with max_num_batched_tokens=%d.",
-                max_num_batched_tokens)
+                self.max_num_batched_tokens)
 
         self.max_num_seqs = max_num_seqs
         self.max_model_len = max_model_len