[NET]: Use BUILD_BUG_ON() for checking size of skb->cb.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a80e445..d56e0d2 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1762,8 +1762,6 @@
 	.owner	= THIS_MODULE,	/* for consistency 8) */
 };
 
-extern void netlink_skb_parms_too_large(void);
-
 static int __init netlink_proto_init(void)
 {
 	struct sk_buff *dummy_skb;
@@ -1775,8 +1773,7 @@
 	if (err != 0)
 		goto out;
 
-	if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb))
-		netlink_skb_parms_too_large();
+	BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
 
 	nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
 	if (!nl_table)