[IPV6]: Use kmemdup

Code diff stats:

[acme@newtoy net-2.6.20]$ codiff /tmp/ipv6.ko.before /tmp/ipv6.ko.after
/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ipv6/ip6_output.c:
  ip6_output      |  -52
  ip6_append_data |   +2
 2 functions changed, 2 bytes added, 52 bytes removed

/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ipv6/addrconf.c:
  addrconf_sysctl_register |  -27
 1 function changed, 27 bytes removed

/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ipv6/tcp_ipv6.c:
  tcp_v6_syn_recv_sock  |  -32
  tcp_v6_parse_md5_keys |  -24
 2 functions changed, 56 bytes removed

/tmp/ipv6.ko.after:
 5 functions changed, 2 bytes added, 135 bytes removed
[acme@newtoy net-2.6.20]$

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 85f8892..e05ecbb 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -624,14 +624,13 @@
 		skb_shinfo(skb)->frag_list = NULL;
 		/* BUILD HEADER */
 
-		tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
+		tmp_hdr = kmemdup(skb->nh.raw, hlen, GFP_ATOMIC);
 		if (!tmp_hdr) {
 			IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 			return -ENOMEM;
 		}
 
 		*prevhdr = NEXTHDR_FRAGMENT;
-		memcpy(tmp_hdr, skb->nh.raw, hlen);
 		__skb_pull(skb, hlen);
 		fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
 		skb->nh.raw = __skb_push(skb, hlen);