Fix a mistake in previous change

PiperOrigin-RevId: 281409019

official/nlp/bert/run_pretraining.py

@@ -59,12 +59,10 @@ def get_pretrain_dataset_fn(input_file_pattern, seq_length,
   """Returns input dataset from input file string."""
   def _dataset_fn(ctx=None):
     """Returns tf.data.Dataset for distributed BERT pretraining."""
-    input_files = []
-    for input_pattern in input_file_pattern.split(','):
-      input_files.extend(tf.io.gfile.glob(input_pattern))
+    input_patterns = input_file_pattern.split(',')
     batch_size = ctx.get_per_replica_batch_size(global_batch_size)
     train_dataset = input_pipeline.create_pretrain_dataset(
-        input_files,
+        input_patterns,
         seq_length,
         max_predictions_per_seq,
         batch_size,