return error when unable to set sound volume

ScStwLibraries/sources/scstwsoundplayer.cpp

@@ -63,6 +63,7 @@ ScStwSoundPlayer::PlayResult ScStwSoundPlayer::play(ScStwSoundPlayer::StartSound
     }
     else {
         qDebug() << "[WARNING][SoundPlayer] Could not determine output device to set volume";
+        return Error;
     }
 
     this->soundEffect->setVolume(1);