use KERNEL_LOCK and KERNEL_UNLOCK instead of fumbling with kernel_lock directly.
use KERNEL_LOCK and KERNEL_UNLOCK instead of fumbling with kernel_lock
directly.

ok kettenis@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars