neigh: directly goto out after setting nud_state to NUD_FAILED

Because those following if conditions will not be matched.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/neighbour.c

@@ -945,6 +945,7 @@ static void neigh_timer_handler(unsigned long arg)
 		neigh->nud_state = NUD_FAILED;
 		notify = 1;
 		neigh_invalidate(neigh);
+		goto out;
 	}
 
 	if (neigh->nud_state & NUD_IN_TIMER) {