dcb: Use rtnl_register_many().

We will remove rtnl_register() in favour of rtnl_register_many().

When it succeeds, rtnl_register_many() guarantees all rtnetlink types
in the passed array are supported, and there is no chance that a part
of message types is not supported.

Let's use rtnl_register_many() instead.

Signed-off-by: Kuniyuki Iwashima <[e-mail]>
Reviewed-by: Eric Dumazet <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/dcb/dcbnl.c

···
 	.notifier_call  = dcbnl_netdevice_event,
 };
 
+static const struct rtnl_msg_handler dcbnl_rtnl_msg_handlers[] __initconst = {
+	{.msgtype = RTM_GETDCB, .doit = dcb_doit},
+	{.msgtype = RTM_SETDCB, .doit = dcb_doit},
+};
+
 static int __init dcbnl_init(void)
 {
 	int err;
···
 	if (err)
 		return err;
 
-	rtnl_register(PF_UNSPEC, RTM_GETDCB, dcb_doit, NULL, 0);
-	rtnl_register(PF_UNSPEC, RTM_SETDCB, dcb_doit, NULL, 0);
+	rtnl_register_many(dcbnl_rtnl_msg_handlers);
 
 	return 0;
 }