process_config_first_time_only: initialize syslog as intended.

process_config_first_time_only: initialize syslog as intended.

On Linux, we previously called openlog() (with different options!) while
initializing SELinux; leave SELinux messages as LOG_USER|LOG_INFO in case
anyone was relying on that, but let the rest of our log messages come
out as LOG_DAEMON.

Also enable LOG_PERROR (copy syslog messages to stderr) unconditionally;
we can make this an autoconf check if anyone's pet Unix doesn't have
LOG_PERROR.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=35358
Reviewed-by: Colin Walters <walters@verbum.org>