sys-devel/distcc: improve init.d script, secure pidfile handling

sys-devel/distcc: improve init.d script, secure pidfile handling

removed unneeded start/stop functions

removed gcc spec/path loading, it's useless because
path whitelist is handled by compiler-shadow and we no longer
use gcc specs.

pidfile is now owned by root and created by s-s-d
pidfile path is now controlled by service name (/run/distccd.pid)
initfile no longer runs chmod on pidfile and parent directory.

Bug: https://bugs.gentoo.org/650854
Package-Manager: Portage-2.3.52, Repoman-2.3.12
Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>