[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/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index ec31690..c0c6194 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -40,7 +40,7 @@
 obj-$(CONFIG_IP_NF_SIP) += ip_conntrack_sip.o
 obj-$(CONFIG_IP_NF_NETBIOS_NS) += ip_conntrack_netbios_ns.o
 
-# NAT helpers 
+# NAT helpers (ip_conntrack)
 obj-$(CONFIG_IP_NF_NAT_H323) += ip_nat_h323.o
 obj-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp.o
 obj-$(CONFIG_IP_NF_NAT_AMANDA) += ip_nat_amanda.o
@@ -49,6 +49,9 @@
 obj-$(CONFIG_IP_NF_NAT_IRC) += ip_nat_irc.o
 obj-$(CONFIG_IP_NF_NAT_SIP) += ip_nat_sip.o
 
+# NAT helpers (nf_conntrack)
+obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o
+
 # generic IP tables 
 obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o