os: remove unneeded errno assignment
os: remove unneeded errno assignment

If socket() fails, it will return failure code. No need to reset errno
beforehand.

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

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