[IPV6]: Remove unneeded pointer idev from addrconf_cleanup().

This trivial patch removes the unneeded pointer idev returned from
__in6_dev_get(), which is never used. The check for NULL can be simply
done by if (__in6_dev_get(dev) == NULL).
Signed-off-by: Micah Gruber <micah.gruber@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/addrconf.c

@@ -4243,7 +4243,6 @@ int __init addrconf_init(void)
 void __exit addrconf_cleanup(void)
 {
 	struct net_device *dev;
-	struct inet6_dev *idev;
 	struct inet6_ifaddr *ifa;
 	int i;
 
@@ -4261,7 +4260,7 @@ void __exit addrconf_cleanup(void)
 	 */
 
 	for_each_netdev(dev) {
-		if ((idev = __in6_dev_get(dev)) == NULL)
+		if (__in6_dev_get(dev) == NULL)
 			continue;
 		addrconf_ifdown(dev, 1);
 	}