Fix kaldi plug-in detection (#2964)

Summary:
Follow-up of f70b970a

Pull Request resolved: https://github.com/pytorch/audio/pull/2964

Reviewed By: xiaohui-zhang

Differential Revision: D42380451

Pulled By: mthrok

fbshipit-source-id: 0569a32be576042ab419b363e694fe7d2db1feb0

torchaudio/_internal/module_utils.py

@@ -68,7 +68,9 @@ def deprecated(direction: str, version: Optional[str] = None):
 
 def is_kaldi_available():
     try:
-        return torch.ops.torchaudio.is_kaldi_available()
+        import torchaudio.lib._torchaudio
+
+        return torchaudio.lib._torchaudio.is_kaldi_available()
     except Exception:
         return False