devlink: Constify the 'table_ops' parameter of devl_dpipe_table_register()

"struct devlink_dpipe_table_ops" only contains some function pointers.

Update "struct devlink_dpipe_table" and the 'table_ops' parameter of
devl_dpipe_table_register() so that structures in drivers can be
constified.

Constifying these structures will move some data to a read-only section, so
increase overall security.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/devlink.h

@@ -352,7 +352,7 @@ struct devlink_dpipe_table {
 	bool resource_valid;
 	u64 resource_id;
 	u64 resource_units;
-	struct devlink_dpipe_table_ops *table_ops;
+	const struct devlink_dpipe_table_ops *table_ops;
 	struct rcu_head rcu;
 };
 
@@ -1751,7 +1751,7 @@ void devl_sb_unregister(struct devlink *devlink, unsigned int sb_index);
 void devlink_sb_unregister(struct devlink *devlink, unsigned int sb_index);
 int devl_dpipe_table_register(struct devlink *devlink,
 			      const char *table_name,
-			      struct devlink_dpipe_table_ops *table_ops,
+			      const struct devlink_dpipe_table_ops *table_ops,
 			      void *priv, bool counter_control_extern);
 void devl_dpipe_table_unregister(struct devlink *devlink,
 				 const char *table_name);

net/devlink/dpipe.c

@@ -839,7 +839,7 @@ EXPORT_SYMBOL_GPL(devlink_dpipe_table_counter_enabled);
  */
 int devl_dpipe_table_register(struct devlink *devlink,
 			      const char *table_name,
-			      struct devlink_dpipe_table_ops *table_ops,
+			      const struct devlink_dpipe_table_ops *table_ops,
 			      void *priv, bool counter_control_extern)
 {
 	struct devlink_dpipe_table *table;