examples fix t2i training (#5001)

* examples fix t2i training

* make style

examples/t2i_adapter/train_t2i_adapter_sdxl.py

@@ -1060,7 +1060,9 @@ def main(args):
     )
 
     # Prepare everything with our `accelerator`.
-    t2iadapter, optimizer, lr_scheduler = accelerator.prepare(t2iadapter, optimizer, lr_scheduler)
+    t2iadapter, optimizer, train_dataloader, lr_scheduler = accelerator.prepare(
+        t2iadapter, optimizer, train_dataloader, lr_scheduler
+    )
 
     # We need to recalculate our total training steps as the size of the training dataloader may have changed.
     num_update_steps_per_epoch = math.ceil(len(train_dataloader) / args.gradient_accumulation_steps)