shell: Remove unused pointer_end_grab
shell: Remove unused pointer_end_grab

shell_grab_end already does that for us.

Signed-off-by: Tiago Vignatti <f080760b2054d506aacc8dee97f8804c19fbc3aa@intel.com>

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