bug#76876: logname output is often wrong when linked with glibc

[Bruno Haible via GNU coreutils Bug Reports]

I wrote:
> With this, coreutils should be fine, since it already imports the 'getlogin'
> module from gnulib.

Verified by comparing coreutils-9.5 with coreutils-HEAD on Alpine Linux 3.20:

With coreutils-9.5:

$ logname
bruno
$ su -
Password:
# logname
root

Now:

$ logname
bruno
$ su -
Password:
# logname
bruno

Paul, Pádraig: How about adding a coreutils/NEWS entry for this bug fix?

Bruno