simple-egl: Remove leftover wl_visual variable
simple-egl: Remove leftover wl_visual variable

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