Fix LibriSpeech Conforner RNN-T eval script (#2666)

Summary:
`ConformerRNNTModule`'s initializer now accepts a SentencePiece model rather than a path to a model as input. This PR corrects `eval.py` accordingly.

Pull Request resolved: https://github.com/pytorch/audio/pull/2666

Reviewed By: carolineechen

Differential Revision: D39386968

Pulled By: hwangjeff

fbshipit-source-id: 95a94dd898263d648650f7376c29810b1456d6c1

examples/asr/librispeech_conformer_rnnt/eval.py

@@ -2,6 +2,8 @@ import logging
 import pathlib
 from argparse import ArgumentParser
 
+import sentencepiece as spm
+
 import torch
 import torchaudio
 from lightning import ConformerRNNTModule
@@ -16,7 +18,8 @@ def compute_word_level_distance(seq1, seq2):
 
 
 def run_eval(args):
-    model = ConformerRNNTModule.load_from_checkpoint(args.checkpoint_path, sp_model_path=str(args.sp_model_path)).eval()
+    sp_model = spm.SentencePieceProcessor(model_file=str(args.sp_model_path))
+    model = ConformerRNNTModule.load_from_checkpoint(args.checkpoint_path, sp_model=sp_model).eval()
     data_module = get_data_module(str(args.librispeech_path), str(args.global_stats_path), str(args.sp_model_path))
 
     if args.use_cuda: