multiplex.sh fails in make tests

[Damien Miller]

On Sun, 6 Jul 2014, Christian Hesse wrote:

> Damien Miller <djm at mindrot.org> on Sat, 2014/07/05 12:34:
> > On Fri, 4 Jul 2014, Christian Hesse wrote:
> > 
> > > Hello everybody,
> > > 
> > > running make tests on latest openssh-portable git master
> > > (V_6_6_P1-114-g72e6b5c) fails:
> > 
> > Yes, I've been trying to figure that out myself. I think this is the fix:
> 
> Works for me. Thanks!

I ended up committing something a bit different after some feedback from
Markus.

-d