logger: do not exit when socket errors are not enforced

logger: do not exit when socket errors are not enforced

The libc openlog(3) does not have error detection whether unix socket
could be opened.  As a side effect that made it possible to use logger
even if syslogd was not running.  Of course user message in these cases
were lost.  This change makes the logger do behave similar way again, so
that sysvinit scripts can successfully pipe messages to logger when ever.

Addresses: https://bugs.debian.org/787864
Addresses: https://bugs.debian.org/790875
Reported-by: Andreas Beckmann <anbe@debian.org>
Reported-by: Andreas Henriksson <andreas@fatal.se>
Tested-by: Robie Basak <robie.basak@ubuntu.com>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>