Bug#871490: mention how to force listing of /var/lib/systemd/coredump

[積丹尼 Dan Jacobson]

>>>>> "MB" == Michael Biebl <biebl at debian.org> writes:

MB> coredumpctl afaik uses the journal to look up coredump entries.
MB> Do the coredumps show up in the journal?

It seems so:
/var/log/syslog.6.gz:Aug  9 00:04:56 jidanni6 systemd-coredump[1801]: Process 1797 (epiphany) of user 1000 dumped core...

MB> Have you enabled persistent journal or not?

I didn't tamper with the defaults.

Anyway the man page should say all the steps the user must do, else the
coredumpctl command will not work out of the box.