audit: don't generate loginuid log when audit disabled

If audit is disabled, we shouldn't generate loginuid audit
log.

Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index df1e685..9ab02fa 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1971,6 +1971,9 @@
 	struct audit_buffer *ab;
 	uid_t uid, ologinuid, nloginuid;
 
+	if (!audit_enabled)
+		return;
+
 	uid = from_kuid(&init_user_ns, task_uid(current));
 	ologinuid = from_kuid(&init_user_ns, koldloginuid);
 	nloginuid = from_kuid(&init_user_ns, kloginuid),