use wakeup here, not wakeup_one - avoids problem of not waking up writers when there are more of them than size of queue waiting, and nothing else going on.
use wakeup here, not wakeup_one - avoids problem of not waking up writers
when there are more of them than size of queue waiting, and nothing else
going on.

ok miod@ kettenis@

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