[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/ipv4/netfilter/nf_nat_proto_unknown.c b/net/ipv4/netfilter/nf_nat_proto_unknown.c
index f50d020..cfd2742 100644
--- a/net/ipv4/netfilter/nf_nat_proto_unknown.c
+++ b/net/ipv4/netfilter/nf_nat_proto_unknown.c
@@ -37,7 +37,7 @@
 }
 
 static int
-unknown_manip_pkt(struct sk_buff **pskb,
+unknown_manip_pkt(struct sk_buff *skb,
 		  unsigned int iphdroff,
 		  const struct nf_conntrack_tuple *tuple,
 		  enum nf_nat_manip_type maniptype)