/etc/init.de/qemu-guest-agent start shows OK despite failing
Had made an own kernel missing virtio serial, qemu guest agent didn't run.
Took some log inspection and internet searching to find out virtio serial could be missing in the kernel.
This bug is minor, yet responsible for two unnecessary reboots because "not working" isn't signaled when it should and comes as a surprise later.
Steps to Reproduce:
1. make kernel missing virtio serial
2. emerge qemu-guest-agent and start script
startup script shows always [OK] despite qemu-ga not being started
startup script should not show [OK] if qemu-ga fails being started