net: phonet: mark phonet_protocol as const

The phonet_protocol structs don't need to be written by anyone and
so can be marked as const.

Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/phonet/pep.c

@@ -1351,7 +1351,7 @@ static struct proto pep_proto = {
 	.name		= "PNPIPE",
 };
 
-static struct phonet_protocol pep_pn_proto = {
+static const struct phonet_protocol pep_pn_proto = {
 	.ops		= &phonet_stream_ops,
 	.prot		= &pep_proto,
 	.sock_type	= SOCK_SEQPACKET,