Made audio output example easier to understand. No real code changes

Maybe it's just me, but every time I try to read the "toggleMode" method
in the audio output example, I get confused on whether I'm switching to/
from push/pull mode, and even what pushing and pulling entails. The name
of the push timer also seemed backwards (which added to the confusion).

Change-Id: I5ff7d18f72490c22b91a948ad7513b402a01c5e4
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>

examples/multimedia/audiooutput/audiooutput.h

@@ -91,7 +91,7 @@ private:
     void createAudioOutput();
 
 private:
-    QTimer *m_pullTimer;
+    QTimer *m_pushTimer;
 
     // Owned by layout
     QPushButton *m_modeButton;
@@ -110,7 +110,7 @@ private:
     QByteArray m_buffer;
 
 private slots:
-    void pullTimerExpired();
+    void pushTimerExpired();
     void toggleMode();
     void toggleSuspendResume();
     void deviceChanged(int index);