neigh: remove dynamic neigh table registration support

Currently there are only three neigh tables in the whole kernel:
arp table, ndisc table and decnet neigh table. What's more,
we don't support registering multiple tables per family.
Therefore we can just make these tables statically built-in.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index c8121ce..7ca7c31 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -591,7 +591,7 @@
 
 void __init dn_neigh_init(void)
 {
-	neigh_table_init(&dn_neigh_table);
+	neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table);
 	proc_create("decnet_neigh", S_IRUGO, init_net.proc_net,
 		    &dn_neigh_seq_fops);
 }
@@ -599,5 +599,5 @@
 void __exit dn_neigh_cleanup(void)
 {
 	remove_proc_entry("decnet_neigh", init_net.proc_net);
-	neigh_table_clear(&dn_neigh_table);
+	neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table);
 }