Silence -Woverloaded-virtual warnings in QRasterPaintEngine

Silence -Woverloaded-virtual warnings in QRasterPaintEngine

The QRasterPaintEngine::updateState() is not a reimplementation of
QPaintEngineEx::updateState(const QPaintEngineState &state). Rename the
updateState() function to updateRasterState(), and ensureState() to
ensureRasterState(). These names were chosen to match the class name
QRasterPaintEngineState on which these functions operate.

../../include/QtGui/5.0.0/QtGui/private/../../../../../src/gui/painting/qpaintengine_raster_p.h:271:10:
warning: 'QRasterPaintEngine::updateState' hides overloaded virtual
function [-Woverloaded-virtual]
    void updateState();
         ^
../../include/QtGui/5.0.0/QtGui/private/../../../../../src/gui/painting/qpaintengineex_p.h:202:18:
note: hidden overloaded virtual function 'QPaintEngineEx::updateState'
declared here
    virtual void updateState(const QPaintEngineState &state);
                 ^

Change-Id: Ie9ff0230019b383d53757029c6b2194dfc6a2664
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>