samba: add support for sysvinit via lsb-init-functions

Since there're surely lot's of individual distibutions not moved to systemd,
allow sane samba start/stop with systemv anyway. Rely on lsb-init-functions
for improved control.

Signed-off-by: Jens Rehsack <sno@netbsd.org>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>