[NETFILTER]: Replace sk_buff ** with sk_buff *

With all the users of the double pointers removed, this patch mops up by
finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_internals.h b/net/netfilter/nf_internals.h
index 0df7fff..196269c 100644
--- a/net/netfilter/nf_internals.h
+++ b/net/netfilter/nf_internals.h
@@ -14,7 +14,7 @@
 
 /* core.c */
 extern unsigned int nf_iterate(struct list_head *head,
-				struct sk_buff **skb,
+				struct sk_buff *skb,
 				int hook,
 				const struct net_device *indev,
 				const struct net_device *outdev,