xfrm: Use separate low and high order bits of the sequence numbers in xfrm_skb_cb

To support IPsec extended sequence numbers, we split the
output sequence numbers of xfrm_skb_cb in low and high order 32 bits
and we add the high order 32 bits to the input sequence numbers.
All users are updated accordingly.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 325053d..4286fd3 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -208,7 +208,7 @@
 
 	ah->reserved = 0;
 	ah->spi = x->id.spi;
-	ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);
+	ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 
 	sg_init_table(sg, nfrags);
 	skb_to_sgvec(skb, sg, 0, skb->len);