Fix bug in train_dreambooth_lora (#3183)

* Update train_dreambooth_lora.py

fix bug

* Update train_dreambooth_lora.py

examples/dreambooth/train_dreambooth_lora.py

@@ -743,7 +743,7 @@ def main(args):
         )
         temp_pipeline._modify_text_encoder(text_lora_attn_procs)
         text_encoder = temp_pipeline.text_encoder
-        accelerator.register_for_checkpointing(unet_lora_layers)
+        accelerator.register_for_checkpointing(text_encoder_lora_layers)
         del temp_pipeline
 
     if args.scale_lr: