fix warning message pipeline loading (#3446)

src/diffusers/pipelines/pipeline_utils.py

@@ -296,8 +296,7 @@ def maybe_raise_or_warn(
 
         if not issubclass(model_cls, expected_class_obj):
             raise ValueError(
-                f"{passed_class_obj[name]} is of type: {type(passed_class_obj[name])}, but should be"
-                f" {expected_class_obj}"
+                f"{passed_class_obj[name]} is of type: {model_cls}, but should be" f" {expected_class_obj}"
             )
     else:
         logger.warning(