window: Remove unused variable
window: Remove unused variable

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