[NET]: Mark struct net_device * argument to netdev_priv const

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -546,7 +546,7 @@ struct net_device
 #define	NETDEV_ALIGN		32
 #define	NETDEV_ALIGN_CONST	(NETDEV_ALIGN - 1)
 
-static inline void *netdev_priv(struct net_device *dev)
+static inline void *netdev_priv(const struct net_device *dev)
 {
 	return (char *)dev + ((sizeof(struct net_device)
 					+ NETDEV_ALIGN_CONST)