net/rtnetlink: remove unused sz_idx variable

The sz_idx variable is defined in the rtnetlink_rcv_msg(), but
not used anywhere. Let's remove it.

Signed-off-by: Alexander Kuleshov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/core/rtnetlink.c

···
 {
 	struct net *net = sock_net(skb->sk);
 	rtnl_doit_func doit;
-	int sz_idx, kind;
+	int kind;
 	int family;
 	int type;
 	int err;
···
 		return 0;
 
 	family = ((struct rtgenmsg *)nlmsg_data(nlh))->rtgen_family;
-	sz_idx = type>>2;
 	kind = type&3;
 
 	if (kind != 2 && !netlink_net_capable(skb, CAP_NET_ADMIN))