[IPSEC]: Fix bogus usage of u64 on input sequence number

Al Viro spotted a bogus use of u64 on the input sequence number which
is big-endian.  This patch fixes it by giving the input sequence number
its own member in the xfrm_skb_cb structure.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 4d6ebc6..62188c6 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -109,7 +109,7 @@
 	if (encap_type < 0) {
 		async = 1;
 		x = xfrm_input_state(skb);
-		seq = XFRM_SKB_CB(skb)->seq;
+		seq = XFRM_SKB_CB(skb)->seq.input;
 		goto resume;
 	}
 
@@ -175,7 +175,7 @@
 
 		spin_unlock(&x->lock);
 
-		XFRM_SKB_CB(skb)->seq = seq;
+		XFRM_SKB_CB(skb)->seq.input = seq;
 
 		nexthdr = x->type->input(x, skb);