Merge "audio policy: fix mutex in stopOutput"

status_t AudioPolicyService::stopOutput(audio_port_handle_t portId)

{

    {

        Mutex::Autolock _l(mLock);

        const ssize_t index = mAudioPlaybackClients.indexOfKey(portId);

        if (index < 0) {

            ALOGE("%s AudioTrack client not found for portId %d", __FUNCTION__, portId);

            return INVALID_OPERATION;

        }

    }

    if (mAudioPolicyManager == NULL) {

        return NO_INIT;

    }