daemon: use socklen_t

daemon: use socklen_t

Windows's accept()-function takes the last argument as an int, but glibc
takes an unsigned int. Use socklen_t to get rid of a warning. This is
basically a revert of 7fa0908, but we have already been depending on
socklen_t existing since June 2006 (commit 5b276ee4). I guess this means
that socklen_t IS defined on OSX after all - at least in recent headers.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>