tdf#98052 - even polygons were not drawn on the alpha device

Change-Id: I5725ec23869b295c8021bef0330ee6f69f206351
Reviewed-on: https://gerrit.libreoffice.org/23024
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
diff --git a/vcl/source/outdev/polygon.cxx b/vcl/source/outdev/polygon.cxx
index 129f6de..1ca1d87 100644
--- a/vcl/source/outdev/polygon.cxx
+++ b/vcl/source/outdev/polygon.cxx
@@ -212,6 +212,8 @@ void OutputDevice::DrawPolygon( const tools::Polygon& rPoly )

        if(bSuccess)
        {
            if( mpAlphaVDev )
                mpAlphaVDev->DrawPolygon( rPoly );
            return;
        }
    }