Uninitialized variable in QTouchEventTouchPointPrivate

Non-static class member rotation is not initialized in this constructor
nor in any functions that it calls.

Change-Id: I2dde99a8cd2107b0cfb4201f641d40b4d0823aa2
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@theqtcompany.com>

src/gui/kernel/qevent_p.h

@@ -65,7 +65,8 @@ public:
         : ref(1),
           id(id),
           state(Qt::TouchPointReleased),
-          pressure(qreal(-1.))
+          pressure(qreal(-1.)),
+          rotation(qreal(0.))
     { }
 
     inline QTouchEventTouchPointPrivate *detach()