VCL canvas: fix another clipping mistake (related: tdf#115142)

Follow-up to 5d710cf7 -
setupOutDevState() tends to set a clip, better not overwrite that.

Change-Id: I52aa7db3ef12e9c2902016460e1bf4914328dc7c
Reviewed-on: https://gerrit.libreoffice.org/50920Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

canvas/source/vcl/canvashelper_texturefill.cxx

@@ -976,7 +976,7 @@ namespace vclcanvas
                             const vcl::Region aPolyClipRegion( aPolyPoly );
 
                             rOutDev.Push( PushFlags::CLIPREGION );
-                            rOutDev.SetClipRegion( aPolyClipRegion );
+                            rOutDev.IntersectClipRegion( aPolyClipRegion );
 
                             textureFill( rOutDev,
                                          *pGrfObj,
@@ -994,7 +994,7 @@ namespace vclcanvas
                                 OutputDevice& r2ndOutDev( mp2ndOutDev->getOutDev() );
                                 r2ndOutDev.Push( PushFlags::CLIPREGION );
 
-                                r2ndOutDev.SetClipRegion( aPolyClipRegion );
+                                r2ndOutDev.IntersectClipRegion( aPolyClipRegion );
                                 textureFill( r2ndOutDev,
                                              *pGrfObj,
                                              aPt,