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/include/linux/hdlc.h b/include/linux/hdlc.h
index e960faa..fd47a15 100644
--- a/include/linux/hdlc.h
+++ b/include/linux/hdlc.h
@@ -43,7 +43,7 @@
 };
 
 
-/* Pointed to by dev->priv */
+/* Pointed to by netdev_priv(dev) */
 typedef struct hdlc_device {
 	/* used by HDLC layer to take control over HDLC device from hw driver*/
 	int (*attach)(struct net_device *dev,