[SCTP]: Introduce sctp_hdr()

For consistency with all the other skb->h.raw accessors.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 08f92ba..7c28c9b 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -235,7 +235,7 @@
 	port = &addr->v4.sin_port;
 	addr->v4.sin_family = AF_INET;
 
-	sh = (struct sctphdr *) skb->h.raw;
+	sh = sctp_hdr(skb);
 	if (is_saddr) {
 		*port  = sh->source;
 		from = &ip_hdr(skb)->saddr;
@@ -731,13 +731,11 @@
 /* Initialize and copy out a msgname from an inbound skb. */
 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
 {
-	struct sctphdr *sh;
-	struct sockaddr_in *sin;
-
 	if (msgname) {
+		struct sctphdr *sh = sctp_hdr(skb);
+		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
+
 		sctp_inet_msgname(msgname, len);
-		sin = (struct sockaddr_in *)msgname;
-		sh = (struct sctphdr *)skb->h.raw;
 		sin->sin_port = sh->source;
 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 	}