OpenSL ES: Don't store or return the adjusted volume level.

According to our own docs we should always return 1.0 (MAX) volume level
if the device doesn't support setting the volume, which is the case
for OpenSL ES on Android.

Task-number: QTBUG-42159
Change-Id: I9144e9e2cd84cc80633c68c5d6fa32b8dbd0fcd5
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>

src/plugins/opensles/qopenslesaudioinput.cpp

@@ -70,7 +70,6 @@ QOpenSLESAudioInput::QOpenSLESAudioInput(const QByteArray &device)
     , m_errorState(QAudio::NoError)
     , m_deviceState(QAudio::StoppedState)
     , m_lastNotifyTime(0)
-    , m_volume(1)
     , m_bufferSize(0)
     , m_periodSize(0)
     , m_intervalTime(1000)
@@ -480,12 +479,12 @@ qint64 QOpenSLESAudioInput::elapsedUSecs() const
 void QOpenSLESAudioInput::setVolume(qreal vol)
 {
     // Volume interface is not available for the recorder on Android
-    m_volume = vol;
+    Q_UNUSED(vol);
 }
 
 qreal QOpenSLESAudioInput::volume() const
 {
-    return m_volume;
+    return qreal(1.0);
 }
 
 void QOpenSLESAudioInput::reset()

src/plugins/opensles/qopenslesaudioinput.h

@@ -113,7 +113,6 @@ private:
     QAudio::State m_deviceState;
     QTime m_clockStamp;
     qint64 m_lastNotifyTime;
-    qreal m_volume;
     int m_bufferSize;
     int m_periodSize;
     int m_intervalTime;