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

[Zoltan Somogyi]

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?
What was the unexpected difference?

The diff is fine.

Zoltan.