[IPVS]: Replace local version of skb_make_writable

This patch removes the IPVS-specific version of skb_make_writable and
replaces it with the netfilter one.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipvs/ip_vs_xmit.c b/net/ipv4/ipvs/ip_vs_xmit.c
index 666e080..afd90d4 100644
--- a/net/ipv4/ipvs/ip_vs_xmit.c
+++ b/net/ipv4/ipvs/ip_vs_xmit.c
@@ -253,7 +253,7 @@
 	}
 
 	/* copy-on-write the packet before mangling it */
-	if (!ip_vs_make_skb_writable(&skb, sizeof(struct iphdr)))
+	if (!skb_make_writable(skb, sizeof(struct iphdr)))
 		goto tx_error_put;
 
 	if (skb_cow(skb, rt->u.dst.dev->hard_header_len))
@@ -529,7 +529,7 @@
 	}
 
 	/* copy-on-write the packet before mangling it */
-	if (!ip_vs_make_skb_writable(&skb, offset))
+	if (!skb_make_writable(skb, offset))
 		goto tx_error_put;
 
 	if (skb_cow(skb, rt->u.dst.dev->hard_header_len))