vcl: Free memory by appropriate dtor

Change-Id: I863251d742374d0a60820d41fec9d467c9ff4bd4
Reviewed-on: https://gerrit.libreoffice.org/19446Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/win/source/gdi/gdiimpl.cxx

@@ -1256,7 +1256,7 @@ bool WinSalGraphicsImpl::setClipRegion( const vcl::Region& i_rClip )
             }
 
             if ( mrParent.mpClipRgnData != mrParent.mpStdClipRgnData )
-                delete [] mrParent.mpClipRgnData;
+                delete [] (BYTE*)mrParent.mpClipRgnData;
         }
     }