[NETFILTER]: nf_nat: add FTP NAT helper port

Add FTP NAT helper.

Split out from Jozsef's big nf_nat patch with a few small fixes by myself.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 9948af0..83694cf 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -45,7 +45,7 @@
 /* per conntrack: application helper private data */
 union nf_conntrack_help {
 	/* insert conntrack helper private data (master) here */
-	struct ip_ct_ftp_master ct_ftp_info;
+	struct nf_ct_ftp_master ct_ftp_info;
 };
 
 #include <linux/types.h>