bug#35793: 27.0.50; Redundant "See" in the ELisp manual

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@gmail.com>
> Date: Sun, 19 May 2019 15:06:57 -0400
> Cc: 35793@debbugs.gnu.org
> 
> Mauro Aranda <maurooaranda@gmail.com> writes:
> 
> >> ../../../doc/misc/gnus.texi:3099: warning: `.' or `,' must follow @xref, 
> >> not `f'.
> >> ../../../doc/misc//gnus-faq.texi:710: warning: `.' or `,' must follow 
> >> @xref, not `f'.
> >
> > Right.  My version of makeinfo (6.1) doesn't warn about that.
> 
> Hmm, I'm using version 4.13 (because it's faster); if newer versions
> don't warn about this, maybe we should ignore these warnings.

I'd like to keep compatibility with old Makeinfo versions, so let's
keep the commas.