Re: protect pmf from network drivers that don't provide if_stop

[Martin Husemann <martin%duskware.de@localhost>]

On Tue, Jun 29, 2021 at 03:46:20PM +0930, Brett Lymn wrote:
> I turned up a fix I had put into my source tree a while back, I think at
> the time the wireless driver (urtwn IIRC) did not set an entry for
> if_stop.

This is a driver bug, we should not work around it but catch it early
and fix it.

Side note: the wifi drivers fiddling with struct ifnet will stop
once the new wifi code gets into the main tree.

Martin