The implement of function netdev_all_upper_get_next_dev_rcu has been
removed in:
	commit 
f1170fd462c6 ("net: Remove all_adj_list and its references")
so delete redundant declaration in header file.
Fixes: f1170fd462c6 ("net: Remove all_adj_list and its references")
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Link: https://lore.kernel.org/r/20211013094702.3931071-1-chenwandun@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 
 bool netdev_has_upper_dev(struct net_device *dev, struct net_device *upper_dev);
 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
                                                     struct list_head **iter);
-struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
-                                                    struct list_head **iter);
 
 #ifdef CONFIG_LOCKDEP
 static LIST_HEAD(net_unlink_list);