QSoundEffect: Set playing to true before starting the audio-device.

When the audio-device starts playing it should be able to read from the
source immediately. The OpenSL plugin would fail because the source was
blocking the audio-device from reading, as the state still was in its
initial state (stopped).

Change-Id: Ia26fa2eb442e239f5209947e6c9cd464b7d976a4
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>

src/multimedia/audio/qsoundeffect_qaudio_p.cpp

@@ -236,10 +236,9 @@ void QSoundEffectPrivate::play()
         setStatus(QSoundEffect::Null);
         return;
     }
+    setPlaying(true);
     if (d->m_audioOutput && d->m_audioOutput->state() == QAudio::StoppedState && d->m_sampleReady)
         d->m_audioOutput->start(d);
-
-    setPlaying(true);
 }
 
 void QSoundEffectPrivate::stop()