bug#52428: 28.0.90; Eshell complains that `processp' is unbound on MS-DOS

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: Eli Zaretskii <eliz@gnu.org>
> Date: Sun, 12 Dec 2021 14:06:35 +0800
> 
> > c:/djgpp/bin $ djecho hello
> >
> > Eshell will complain that `processp' is unbound, because there are two
> > uses of `processp' in `eshell-eval-command' that need to be replaced
> > with `eshell-processp'.
> 
> If nobody minds, I'll fix this on the release branch by replacing those
> calls with `eshell-processp'.
> 
> Eli, is that okay?

Yes, of course.  Eshell should never directly call 'processp', except
perhaps in code that makes no sense and isn't called on MS-DOS.