QtMultimedia: Fix compiler warnings.

Change-Id: I5783b1f6dce645fb473e7d3da0911dbb40e3951b
Reviewed-by: Jonathan Liu <net147@gmail.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/multimedia/audio/qaudiodeviceinfo_win32_p.cpp

@@ -309,7 +309,7 @@ void QAudioDeviceInfoInternal::updateLists()
 {
     // redo all lists based on current settings
     bool match = false;
-    DWORD fmt = NULL;
+    DWORD fmt = 0;
 
     if(mode == QAudio::AudioOutput) {
         WAVEOUTCAPS woc;

src/multimedia/recording/qmediarecorder.cpp

@@ -188,7 +188,8 @@ void QMediaRecorderPrivate::_q_applySettings()
 void QMediaRecorderPrivate::_q_availabilityChanged(QtMultimedia::AvailabilityStatus availability)
 {
     Q_Q(QMediaRecorder);
-    Q_UNUSED(error);
+    Q_UNUSED(error)
+    Q_UNUSED(availability)
 
     // Really this should not always emit, but
     // we can't really tell from here (isAvailable

src/plugins/directshow/camera/camera.pri

@@ -13,7 +13,6 @@ HEADERS += \
     $$PWD/dsvideodevicecontrol.h \
     $$PWD/dsimagecapturecontrol.h \
     $$PWD/dscamerasession.h \
-    $$PWD/dscameraservice.h \
     $$PWD/directshowglobal.h
 
 SOURCES += \