AudioInput: read data if our own buffer is empty

Change-Id: If56905f3544f751a43e7a44ced87e5faa01cd458

src/media/audio/audio_input.cpp

@@ -112,7 +112,7 @@ AudioInput::readFromDevice()
             while (ringBuf_ && ringBuf_->isEmpty())
                 readFromFile();
         if (playingFile_) {
-            while (ringBuf_ && ringBuf_->isEmpty())
+            while (ringBuf_ && ringBuf_->getLength(id_) == 0)
                 readFromQueue();
         }
     }