[m-rev.] diff: fix the libbrary check_doc target

[Zoltan Somogyi]

On Mon, 3 Jan 2022 00:46:47 +1100 (AEDT), Julien Fischer <jfischer at opturion.com> wrote:
> There's nothing to say that comparison function is the one the sort
> utility is using (which IIRC is affected by things like the locale
> setting).

That is true.

> In any case, you do sort the list using sort in the undoc case; I just
> figured the line was accidently omitted in the doc case.

No, it wasn't. The sort in the check_undoc target was to move
mer_std.m to the right place in the list, and there is no similar
"file but not really a module" in the check_doc action.

Zoltan.