Throw a warning if we cannot open the audit socket as a session bus

This will effectively print a warning when failing to open the audit
socket running as a session bus.

The call to audit_open() should succeed even if the dbus-daemon doesn't
have the CAP_AUDIT_WRITE capability.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=83856Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>

bus/audit.c

@@ -67,10 +67,6 @@ bus_audit_init (BusContext *context)
       if (e == EINVAL || e == EPROTONOSUPPORT || e == EAFNOSUPPORT)
         return;
 
-      /* If user bus, bail out */
-      if (e == EPERM && getuid () != 0)
-        return;
-
       bus_context_log (context, DBUS_SYSTEM_LOG_WARNING,
                        "Failed to open connection to the audit subsystem: %s",
                        _dbus_strerror (e));