net: constify struct inet6_protocol

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 1640406..b265b70 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1172,7 +1172,7 @@
 	return segs;
 }
 
-static struct inet6_protocol udpv6_protocol = {
+static const struct inet6_protocol udpv6_protocol = {
 	.handler	=	udpv6_rcv,
 	.err_handler	=	udpv6_err,
 	.gso_send_check =	udp6_ufo_send_check,