Fix problem in A2DP interface closeOutputStream().

If the output stream handler passed was not the A2DP output stream, the request was ignored instead of being forwarded downstream to hardware interface.

libs/audioflinger/A2dpAudioInterface.cpp

@@ -89,7 +89,7 @@ AudioStreamOut* A2dpAudioInterface::openOutputStream(
 
 void A2dpAudioInterface::closeOutputStream(AudioStreamOut* out) {
     if (mOutput == 0 || mOutput != out) {
-        LOGW("Attempt to close invalid output stream");
+        mHardwareInterface->closeOutputStream(out);
     }
     else {
         delete mOutput;