clearing grub flag doesn't work on transactional server

[fcrozat]

From logs:

health-checker[1762]: Clearing GRUB flag
health-checker[1762]: grub2-editenv : error: can't open " /boot/grub2/gruben" : Read-only filesystem

[laenion]

It does work, it just prints that error message; the health_checker_flag variable is stored in the Btrfs header, so setting the variable there does work.

See https://bugzilla.opensuse.org/show_bug.cgi?id=1126900 for the current discussion on how to get rid of the message and adding the possibility to store non-special variables.