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>

drivers/net/sunbmac.c

@@ -1233,7 +1233,7 @@ fail_and_cleanup:
 				  bp->bmac_block,
 				  bp->bblock_dvma);
 
-	/* This also frees the co-located 'dev->priv' */
+	/* This also frees the co-located private data */
 	free_netdev(dev);
 	return -ENODEV;
 }