net: constify struct net_protocol

Remove long removed "inet_protocol_base" declaration.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ipcomp.c

diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index 3262ce0..38fbf04 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -146,7 +146,7 @@
 	.output		= ipcomp_output
 };
 
-static struct net_protocol ipcomp4_protocol = {
+static const struct net_protocol ipcomp4_protocol = {
 	.handler	=	xfrm4_rcv,
 	.err_handler	=	ipcomp4_err,
 	.no_policy	=	1,