Properly set the IFF_OACTIVE flag if all the descriptrs are in use for the TX ring and clear the flag when some have been freed.
Properly set the IFF_OACTIVE flag if all the descriptrs are in use for
the TX ring and clear the flag when some have been freed.

ok dlg@ kettenis@

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