shell: free memory on move/resize error paths
shell: free memory on move/resize error paths

Memory leaks noticed by Valgrind, when wl_input_device_update_grab()
fails.

Signed-off-by: Pekka Paalanen <6c0263d81461c956d504307112a4ce25eaacc3d1@gmail.com>

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