bug#25157: 26.0.50; whitespace-cleanup does not remove single trailing empty line anymore

[npostavs]

Reuben Thomas <rrt@sc3d.org> writes:

>(I was trying to make it match ALL the whitespace at the end of the
>buffer, as you probably realised.)

Oh, I thought that might have been the case.  It explains why you were
going through all that trouble with the regexp.

>
> The only thing I'd change in your match is, as in mine, remove the FIXME 
> after save-match-data.​

    (whitespace-cleanup): Remove a FIXME: the reason for save-match-data
    is the call of re-search-forward.

I'm not sure this is a sufficient explanation of why save-match-data is
needed.  Usually in Emacs the caller is responsible for saving the match
data, if it needs to.  I don't really see the need here.