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/eexpress.c b/drivers/net/eexpress.c
index a125e41..9ff3f2f 100644
--- a/drivers/net/eexpress.c
+++ b/drivers/net/eexpress.c
@@ -1046,7 +1046,7 @@
 /*
  * Sanity check the suspected EtherExpress card
  * Read hardware address, reset card, size memory and initialize buffer
- * memory pointers. These are held in dev->priv, in case someone has more
+ * memory pointers. These are held in netdev_priv(), in case someone has more
  * than one card in a machine.
  */