fix bug for blank audio (#1656)

jianganghan

2024-04-25 f8b4924060bb849680925e81ddf1e10ca406c225

 runtime/onnxruntime/src/funasrruntime.cpp

@@ -343,7 +343,7 @@
            return p_result;
        }
      if(offline_stream->UseVad()){
         audio.Split(offline_stream);
         audio.CutSplit(offline_stream);
      }

      float* buff;