Fix some static analysis defects.

A few silly errors, a few unlikely errors, a few changes that should
not have resulted in a problem but makes the code clearer.

Change-Id: Id2c82e9317d53822e4da13c94dec9595ea33b07a
Reviewed-by: Ling Hu <ling.hu@nokia.com>
Reviewed-by: Dmytro Poplavskiy <dmytro.poplavskiy@nokia.com>

src/multimedia/playback/qmediaplayer.cpp

@@ -110,6 +110,7 @@ public:
         , error(QMediaPlayer::NoError)
         , filterStates(false)
         , playlist(0)
+        , networkAccessControl(0)
     {}
 
     QMediaServiceProvider *provider;