PS:
Did you check, if systemd-sysv-generator works?
Run
systemctl status rtirq
if you use the tab key it will become
systemctl status rtirq.service
but you don't need to add ".service".
[weremouse@moonstudio ~]$ systemctl status rtirq.service
● rtirq.service - LSB: Realtime IRQ thread tunning.
Loaded: loaded (/etc/init.d/rtirq; bad; vendor preset: enabled)
Active: active (exited) since Wed 2016-11-30 09:39:16 CET; 1h 1min ago
Docs: man:systemd-sysv-generator(8)
Process: 737 ExecStart=/etc/init.d/rtirq start (code=exited, status=0/SUCCESS)
Nov 30 09:39:14 moonstudio systemd[1]: Starting LSB: Realtime IRQ thread tunning....
Nov 30 09:39:16 moonstudio rtirq[737]: Setting IRQ priorities: start [snd_hdsp] irq=18
pid=392 prio=90: OK.
Nov 30 09:39:16 moonstudio systemd[1]: Started LSB: Realtime IRQ thread tunning..