wayland-server: reduce use of magic numbers
wayland-server: reduce use of magic numbers

Make it clear what the significance of '5' and '113' actually is.
Also drop an unneeded function argument.

bitfactor/wayland,sir-murray/wayland,sir-murray/wayland,mchalupa/wayland,mchalupa/wayland,bitfactor/wayland,abooij/wayland,sir-murray/wayland,tulcod/wayland,abooij/wayland,bitfactor/wayland,tulcod/wayland,mchalupa/wayland,abooij/wayland,tulcod/wayland,eyolfson/wayland,eyolfson/wayland,eyolfson/wayland