evdev: remove signed value checks
evdev: remove signed value checks

Very likely that 2.4 kernels won't be used with Wayland compositor so the
check for signal value is pretty much useless.

It's okay to change e->value inside evdev_process_absolute_motion_touchpad
given it's not used later on, and I also rather not touch this snip because it
will be changed when multi-touch support arrives.

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

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