IPv6 window scaling factor always 1 on initial SYN

[sthaug at nethelp.no]

> > I changed it, and that worked like a dream. Now I get basically the
> > same throughput with IPv4 and IPv6. There are of course still issues
> > like lots of IPv6 tunnels that add extra latency - but that's not the
> > fault of FreeBSD.
> >
> > Anyway, thanks for your work. Below is a context diff (against 7-STABLE
> > cvsupped last night). Do we need a PR to get this into FreeBSD?
> 
> It's in HEAD now as of SVN r190800.

Excellent news, thank you! And presumably we'll get a MFC after a
suitable settling time?

Steinar Haug, Nethelp consulting, sthaug at nethelp.no