[Bugfix] Fix profiling.py (#16202)

Signed-off-by: zh Wang <rekind133@outlook.com>

examples/offline_inference/profiling.py

@@ -234,9 +234,8 @@ def run_profile(context: ProfileContext, csv_output: Optional[str],
             sampling_params.max_tokens = next(output_len_generator)
             assert isinstance(sampling_params.max_tokens, int)
 
-            prompt_token_ids = torch.randint(
-                llm.llm_engine.model_config.get_vocab_size(),
-                size=(prompt_len, )).tolist()
+            prompt_token_ids = torch.randint(llm.get_tokenizer().vocab_size,
+                                             size=(prompt_len, )).tolist()
 
             llm.llm_engine.add_request(
                 request_id=f"seq{i}",