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/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt
index d0f71fc..a2ab6a0 100644
--- a/Documentation/networking/netdevices.txt
+++ b/Documentation/networking/netdevices.txt
@@ -18,7 +18,7 @@
 alloc_etherdev, alloc_netdev.  These reserve extra space for driver
 private data which gets freed when the network device is freed. If
 separately allocated data is attached to the network device
-(dev->priv) then it is up to the module exit handler to free that.
+(netdev_priv(dev)) then it is up to the module exit handler to free that.
 
 MTU
 ===