compositor-drm: do not scan out transformed surfaces
compositor-drm: do not scan out transformed surfaces

Not sure this check belongs here, but as the position checks are here
too, I added this. Just so we don't forget.

Signed-off-by: Pekka Paalanen <6c0263d81461c956d504307112a4ce25eaacc3d1@gmail.com>

Tarnyko/weston-xdg_surface_present,eyolfson/weston,Gnurou/weston,krezovic/weston,jonnylamb/weston,jonnylamb/weston,xorgy/weston,mchalupa/weston,Gnurou/weston,Fantu/compositor-spice,kwm81/weston,sir-murray/weston,sir-murray/weston,Fantu/compositor-spice,udoprog/weston,mchalupa/weston,Tarnyko/weston-xdg_surface_present,kwm81/weston,giucam/weston,giucam/weston,Fantu/compositor-spice,udoprog/weston,krezovic/weston,eyolfson/weston,xorgy/weston