ibmveth: fix kobj_to_dev.cocci warnings

Use kobj_to_dev() instead of container_of()

Generated by: scripts/coccinelle/api/kobj_to_dev.cocci
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Lijun Pan <lijunp213@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmveth.c

@@ -1799,8 +1799,7 @@ static ssize_t veth_pool_store(struct kobject *kobj, struct attribute *attr,
 	struct ibmveth_buff_pool *pool = container_of(kobj,
 						      struct ibmveth_buff_pool,
 						      kobj);
-	struct net_device *netdev = dev_get_drvdata(
-	    container_of(kobj->parent, struct device, kobj));
+	struct net_device *netdev = dev_get_drvdata(kobj_to_dev(kobj->parent));
 	struct ibmveth_adapter *adapter = netdev_priv(netdev);
 	long value = simple_strtol(buf, NULL, 10);
 	long rc;