fix(mmmu_pro): use post_prompt for vision-only doc_to_text

Author: ts-kim

lmms_eval/tasks/mmmu_pro/utils.py

@@ -52,7 +52,7 @@ def mmmu_pro_doc_to_text(doc, lmms_eval_specific_kwargs=None):
         return mmmu_doc_to_text_qwen3vl(doc, lmms_eval_specific_kwargs)
 
     post_prompt = lmms_eval_specific_kwargs["post_prompt"]
-    question = doc.get("question", "")
+    question = post_prompt  # vision-only fallback: question and options are rendered in the image
     if "question" in doc and "options" in doc:  # original operation
         question = construct_prompt(doc, post_prompt)
         if config["metadata"]["interleaved_format"]: