fix incorrect in usage/evaluate

README.md

@@ -59,7 +59,7 @@ def speech_file_to_array_fn(batch):
 	batch["speech"] = resampler(speech_array).squeeze().numpy()
 	return batch
 
-test_dataset = test_dataset.map(speech_file_to_array_fn)
+test_dataset = test_dataset.map(speech_file_to_array_fn).map(th_tokenize)
 inputs = processor(test_dataset["speech"][:2], sampling_rate=16_000, return_tensors="pt", padding=True)
 
 with torch.no_grad():
@@ -122,7 +122,7 @@ def evaluate(batch):
 	batch["pred_strings"] = processor.batch_decode(pred_ids)
 	return batch
 
-result = test_dataset.map(evaluate, batched=True, batch_size=8).map(th_tokenize)
+result = test_dataset.map(evaluate, batched=True, batch_size=8)
 
 print("WER: {:2f}".format(100 * wer.compute(predictions=result["pred_strings"], references=result["sentence"])))
 ```