Delete the screen event handler after its last user.

Change-Id: I2e3c6d08c0dcdd4b954570e9a2198c190c8fffd2
Reviewed-by: Kevin Krammer <kevin.krammer@kdab.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>

src/plugins/platforms/qnx/qqnxintegration.cpp

@@ -149,7 +149,6 @@ QQnxIntegration::~QQnxIntegration()
     qDebug() << "QQnx: platform plugin shutdown begin";
 #endif
 
-    delete m_screenEventHandler;
 
     delete m_nativeInterface;
 
@@ -170,6 +169,8 @@ QQnxIntegration::~QQnxIntegration()
     // Stop/destroy navigator thread
     delete m_navigatorEventHandler;
 
+    delete m_screenEventHandler;
+
     // Destroy all displays
     destroyDisplays();