x11-wm/plasma5-kwin: pacify portlint after 46c2184d862f

WARN: x11-wm/plasma5-kwin/files/patch-src_backends_x11_windowed_x11windowedqpainter__backend.cpp: patch was not generated using `make makepatch''. It is recommended to use `make makepatch'' when you need to [re-]generate a patch to ensure proper patch format.