net: Document that dev_get_stats() returns the given pointer

Document that dev_get_stats() returns the same stats pointer it was
given.  Remove const qualification from the returned pointer since the
caller may do what it likes with that structure.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -2130,7 +2130,7 @@ extern void		netdev_features_change(struct net_device *dev);
 /* Load a device via the kmod */
 extern void		dev_load(struct net *net, const char *name);
 extern void		dev_mcast_init(void);
-extern const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
+extern struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
 					       struct rtnl_link_stats64 *storage);
 extern void		dev_txq_stats_fold(const struct net_device *dev,
 					   struct rtnl_link_stats64 *stats);

net/core/dev.c

@@ -5323,12 +5323,12 @@ static void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
  *	@dev: device to get statistics from
  *	@storage: place to store stats
  *
- *	Get network statistics from device. The device driver may provide
- *	its own method by setting dev->netdev_ops->get_stats64 or
- *	dev->netdev_ops->get_stats; otherwise the internal statistics
- *	structure is used.
+ *	Get network statistics from device. Return @storage.
+ *	The device driver may provide its own method by setting
+ *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
+ *	otherwise the internal statistics structure is used.
  */
-const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
+struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
 					struct rtnl_link_stats64 *storage)
 {
 	const struct net_device_ops *ops = dev->netdev_ops;