input: use tmp var in pointer_unmap_sprite
input: use tmp var in pointer_unmap_sprite

Remove lots of repeated indirection.

Signed-off-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

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