net/handshake: handshake_genl_notify() shouldn't ignore @flags

Reported-by: Dan Carpenter <[e-mail]>
Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests")
Reviewed-by: Simon Horman <[e-mail]>
Signed-off-by: Chuck Lever <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

net/handshake/netlink.c

···
 				proto->hp_handler_class))
 		return -ESRCH;
 
-	msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, flags);
 	if (!msg)
 		return -ENOMEM;