When switching mode inherit the TUN_NBIO and TUN_ASYNC flags and clear these flags on close.  OK mpf@
When switching mode inherit the TUN_NBIO and TUN_ASYNC flags and clear
these flags on close.  OK mpf@

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