netdevice: safe convert to netdev_priv() #part-1

We have some reasons to kill netdev->priv:
1. netdev->priv is equal to netdev_priv().
2. netdev_priv() wraps the calculation of netdev->priv's offset, obviously
   netdev_priv() is more flexible than netdev->priv.
But we cann't kill netdev->priv, because so many drivers reference to it
directly.

This patch is a safe convert for netdev->priv to netdev_priv(netdev).
Since all of the netdev->priv is only for read.
But it is too big to be sent in one mail.
I split it to 4 parts and make every part smaller than 100,000 bytes,
which is max size allowed by vger.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/atp.c b/drivers/net/atp.c
index 405c2dc..7028b27 100644
--- a/drivers/net/atp.c
+++ b/drivers/net/atp.c
@@ -912,7 +912,8 @@
 	struct net_device *next_dev;
 
 	while (root_atp_dev) {
-		next_dev = ((struct net_local *)root_atp_dev->priv)->next_module;
+		struct net_local *atp_local = netdev_priv(root_atp_dev);
+		next_dev = atp_local->next_module;
 		unregister_netdev(root_atp_dev);
 		/* No need to release_region(), since we never snarf it. */
 		free_netdev(root_atp_dev);