tests: Rename left-over caps_mask to capability
tests: Rename left-over caps_mask to capability

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