audit: make audit_log_common_recv_msg() a void function

It always returns zero and no one is checking the return value.
Signed-off-by: Paul Moore <pmoore@redhat.com>

kernel/audit.c

@@ -701,24 +701,22 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
 	return err;
 }
 
-static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
+static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
 {
 	uid_t uid = from_kuid(&init_user_ns, current_uid());
 	pid_t pid = task_tgid_nr(current);
 
 	if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
 		*ab = NULL;
-		return 0;
+		return;
 	}
 
 	*ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
 	if (unlikely(!*ab))
-		return 0;
+		return;
 	audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
 	audit_log_session_info(*ab);
 	audit_log_task_context(*ab);
-
-	return 0;
 }
 
 int is_audit_feature_set(int i)