smc: generic netlink family should be __ro_after_init

The generic netlink family is only initialized during module init,
so it should be __ro_after_init like all other generic netlink
families.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_pnet.c

@@ -461,7 +461,7 @@ static const struct genl_ops smc_pnet_ops[] = {
 };
 
 /* SMC_PNETID family definition */
-static struct genl_family smc_pnet_nl_family = {
+static struct genl_family smc_pnet_nl_family __ro_after_init = {
 	.hdrsize = 0,
 	.name = SMCR_GENL_FAMILY_NAME,
 	.version = SMCR_GENL_FAMILY_VERSION,