journald: disable audit support completely from the journal

This patch not only prevents journald to enable audit system
unconditionally very early at boot but also prevents it to receive
audit messages for the audit netlink and to push them into the
journal.

The first reason is that when journald enables kernel audit, it does
not disable syscall audit (it doesn't load the audit rules), which
introduced a global performance hit. This can be minimized if audit
service is started but that's not the case for all systems.

The second reason is that for systems where audit was disabled by
default they will suddenly have audit enabled (unless audit=0 was
already passed to the kernel command line). This means tons of audit
messages will be sent to dmesg, syslog, journal files, etc...

Note also that audit messages are duplicated in the journal since they
are received both from kmsg and from the audit netlink. A related bug
report can be found here:
https://bugzilla.redhat.com/show_bug.cgi?id=1160046.

This basically reverts the following upstream commits:

 - 875c2e2
 - 4d9ced9

Upstream issue:
systemd/systemd#959

So disable all of this for now until a better option is found or
someone comes up with a real use case.

[fbui: bsc#984034]

src/journal/journald-server.c

@@ -1841,8 +1841,8 @@ int server_init(Server *s) {
         if (r < 0)
                 return r;
 
-        /* Unless we got *some* sockets and not audit, open audit socket */
-        if (s->audit_fd >= 0 || no_sockets) {
+        /* Suse: disable audit messages in journal entirely. */
+        if (false && no_sockets) {
                 r = server_open_audit(s);
                 if (r < 0)
                         return r;