devlink: Constify devlink instance pointer

Constify devlink instance pointer while checking if reload operation is
supported or not.

This helps to review the scope of checks done in reload.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/devlink.c

@@ -2921,7 +2921,7 @@ static void devlink_reload_netns_change(struct devlink *devlink,
 				     DEVLINK_CMD_PARAM_NEW);
 }
 
-static bool devlink_reload_supported(struct devlink *devlink)
+static bool devlink_reload_supported(const struct devlink *devlink)
 {
 	return devlink->ops->reload_down && devlink->ops->reload_up;
 }