netdevice: Kill netdev->priv

This is the last shoot of this series.
After I removing all directly reference of netdev->priv, I am killing
"priv" of "struct net_device" and fixing relative comments/docs.

Anyone will not be allowed to reference netdev->priv directly.
If you want to reference the memory of private data, use netdev_priv()
instead.
If the private data is not allocted when alloc_netdev(), use
netdev->ml_priv to point that memory after you creating that private
data.

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 7028b27..1d6b74c 100644
--- a/drivers/net/atp.c
+++ b/drivers/net/atp.c
@@ -420,7 +420,7 @@
    registers that "should" only need to be set once at boot, so that
    there is non-reboot way to recover if something goes wrong.
 
-   This is an attachable device: if there is no dev->priv entry then it wasn't
+   This is an attachable device: if there is no private entry then it wasn't
    probed for at boot-time, and we need to probe for it again.
    */
 static int net_open(struct net_device *dev)