Refactor: fencer: Rename out to logger_out in pacemaker-fenced.c

This is in preparation for using formatted output in general in
pacemaker-fenced. This change is modeled after pacemaker-schedulerd.c,
specifically commits 35e90c1, 480a5e8, and fdb1cb1.

Ref T604

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>