[NETFILTER]: Introduce nf_inet_address

A few netfilter modules provide their own union of IPv4 and IPv6
address storage. Will unify that in this patch series.

(1/4): Rename union nf_conntrack_address to union nf_inet_addr and
move it to x_tables.h.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 6df2590..6770baf 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -358,7 +358,7 @@
 	unsigned int matchlen, matchoff;
 	struct nf_ct_ftp_master *ct_ftp_info = &nfct_help(ct)->help.ct_ftp_info;
 	struct nf_conntrack_expect *exp;
-	union nf_conntrack_address *daddr;
+	union nf_inet_addr *daddr;
 	struct nf_conntrack_man cmd = {};
 	unsigned int i;
 	int found = 0, ends_in_nl;