init.d/vz-gentoo: don't call tools by absolute path
Apparently in recent Gentoo the ip tool was moved from /sbin to /bin,
so this initscript stopped working.
Apparently runscript makes sure all the needed directories are in PATH
(I have tested with runscript from baselayout-188.8.131.52, pretty old one)
so we can just drop the /sbin/ prefix.
While at it, do it not only for ip, but also for modprobe and sysctl.
Reported-by: Andrei Vinogradov <email@example.com>
Reported-by: Joakim <firstname.lastname@example.org>
Signed-off-by: Kir Kolyshkin <email@example.com>