Update collator.py

Former-commit-id: 941fa8a0d9c3a9106ad0af6e776db7e57f69548f

src/llamafactory/data/collator.py

@@ -99,8 +99,8 @@ class MultiModalDataCollatorForSeq2Seq(DataCollatorForSeq2Seq):
 
         features: Dict[str, "torch.Tensor"] = super().__call__(features)
         features.update(mm_inputs)
-        if features.get("pixel_values") is not None and isinstance(features["pixel_values"], list):
-            features = features.data
+        if isinstance(features.get("pixel_values"), list):  # for pixtral inputs
+            features = features.data  # use default_collate() instead of BatchEncoding.to()
 
         return features