replace `per_gpu_eval_batch_size` with `per_device_eval_batch_size` in readme...

replace `per_gpu_eval_batch_size` with `per_device_eval_batch_size` in readme of multiple-choice task (#25078)

replace `per_gpu_eval_batch_size` with `per_device_eval_batch_size`
in readme of multiple-choice

examples/pytorch/multiple-choice/README.md

@@ -28,7 +28,7 @@ python examples/multiple-choice/run_swag.py \
 --learning_rate 5e-5 \
 --num_train_epochs 3 \
 --output_dir /tmp/swag_base \
---per_gpu_eval_batch_size=16 \
+--per_device_eval_batch_size=16 \
 --per_device_train_batch_size=16 \
 --overwrite_output
 ```