fib: Return the correct errno code

When kalloc or kmemdup failed, should return ENOMEM rather than ENOBUF.
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/fib_rules.c

@@ -1168,7 +1168,7 @@ static void notify_rule_change(int event, struct fib_rule *rule,
 {
 	struct net *net;
 	struct sk_buff *skb;
-	int err = -ENOBUFS;
+	int err = -ENOMEM;
 
 	net = ops->fro_net;
 	skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);