Fix preprocess_function in run_summarization_flax.py (#14769)

Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

examples/flax/summarization/run_summarization_flax.py

@@ -533,7 +533,7 @@ def main():
 
         model_inputs["labels"] = labels["input_ids"]
         decoder_input_ids = shift_tokens_right_fn(
-            jnp.array(labels["input_ids"]), config.pad_token_id, config.decoder_start_token_id
+            labels["input_ids"], config.pad_token_id, config.decoder_start_token_id
         )
         model_inputs["decoder_input_ids"] = np.asarray(decoder_input_ids)