[NETFILTER]: nf_conntrack: mark protocols __read_mostly

Also remove two unnecessary EXPORT_SYMBOLs and move the
nf_conntrack_l3proto_ipv4 declaration to the correct file.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_proto_udp.c b/net/netfilter/nf_conntrack_proto_udp.c
index 3620ecc..13d94a0 100644
--- a/net/netfilter/nf_conntrack_proto_udp.c
+++ b/net/netfilter/nf_conntrack_proto_udp.c
@@ -191,7 +191,7 @@
 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 #endif /* CONFIG_SYSCTL */
 
-struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 =
+struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
 {
 	.l3proto		= PF_INET,
 	.l4proto		= IPPROTO_UDP,
@@ -218,7 +218,7 @@
 };
 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
 
-struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 =
+struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
 {
 	.l3proto		= PF_INET6,
 	.l4proto		= IPPROTO_UDP,