Adjust wording of two fall-through comments

[Jonathan Nieder]

Joseph Myers wrote:

> In two places in glibc, -Wextra produces implicit-fallthrough warnings
> where there are comments about the fall-through but their wording
> doesn't match one of the forms expected by the default
> implicit-fallthrough level.  This patch adjusts those two places to
> have a comment in a form that is accepted, so avoiding the warning
> (this seems preferable to only being able to use a looser level of the
> warning that allows any comment at all as evidence of deliberate
> fall-through).
>
> Tested for x86_64.
>
> 2019-02-13  Joseph Myers  <joseph@codesourcery.com>
>
> 	* iconvdata/cns11643.h (ucs4_to_cns11643): Adjust fall-through
> 	comment wording.
> 	* nis/nis_call.c (__do_niscall3): Likewise.

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>

Thanks.