Fix logging initialization

This is temporary to make a minimal working initialization.  Aside
from doing the ring buffer work, the use of cur_logfile_name needs
to be fixed.  This patch makes write_to_file consistant with its
siblings but mixing lf_private (the file path) and cur_logfile_name
is not good.  Next step is to remove cur_logfile_name entirely.

Also, there is a mixed metaphor here.  Case in point is SetDefaultLogging
that takes either a facility "name" or a log path.  This is broken.
There is code in this function that needs to be run but if the facility
is the keeper of path names for the "FILE" facility, then it should be
its keeper.

Signed-off-by: Jim Lieb <jlieb@panasas.com>