SFT example: Use correct source for max_seq_length (#2474)

When using Unsloth the SFT example used the wrong source for the `max_seq_length` attribute.
The attribute originates from TRL/TrainingArguments.

---

Co-authored-by: gufengke <gufengke@pinduoduo.com>
Co-authored-by: githubnemo <githubnemo@users.noreply.github.com>

Author: 3 people

examples/sft/utils.py

@@ -122,7 +122,7 @@ def create_and_prepare_model(args, data_args, training_args):
         # Load model
         model, _ = FastLanguageModel.from_pretrained(
             model_name=args.model_name_or_path,
-            max_seq_length=data_args.max_seq_length,
+            max_seq_length=training_args.max_seq_length,
             dtype=None,
             load_in_4bit=args.use_4bit_quantization,
         )
@@ -198,7 +198,7 @@ def create_and_prepare_model(args, data_args, training_args):
             else args.lora_target_modules,
             use_gradient_checkpointing=training_args.gradient_checkpointing,
             random_state=training_args.seed,
-            max_seq_length=data_args.max_seq_length,
+            max_seq_length=training_args.max_seq_length,
         )
 
     return model, peft_config, tokenizer