bug#27230: eldoc doc

[Charles A. Roelli]

> Cc: pok@netfonds.no, 27230@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Thu, 21 Sep 2017 17:23:22 +0300
> 
> Hey Charles,
> 
> On 9/20/17 9:12 PM, Charles A. Roelli wrote:
> > Sorry, I had forgotten to update the docstring.  Updated patch
> > attached.
> 
> Is there a reason you so strongly insist on returning to the original 
> calling convention?

Yes, and another user gave an opinion too.  What do others think?