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

[Julien Fischer]

On Mon, 3 Jan 2022, Zoltan Somogyi wrote:

> On Sun, 2 Jan 2022 23:35:27 +1100 (AEDT), Julien Fischer <jfischer at opturion.com> wrote:
>> library/Mmakefile:
>>       Sort the list of modules obtained from mmc --output-stdlib-modules.
>
> I thought that list was already sorted, which meant any subsequence
> of it must also be sorted. Was it not sorted by the same comparison function?

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).

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.

Julien.