neighbour: delete neigh_lookup_nodev as not used

neigh_lookup_nodev isn't used in the kernel after removal
of DECnet. So let's remove it.

Fixes: 1202cdd ("Remove DECnet support from kernel")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/eb5656200d7964b2d177a36b77efa3c597d6d72d.1678267343.git.leonro@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/neighbour.h

@@ -336,8 +336,6 @@ void neigh_table_init(int index, struct neigh_table *tbl);
 int neigh_table_clear(int index, struct neigh_table *tbl);
 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 			       struct net_device *dev);
-struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
-				     const void *pkey);
 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
 				 struct net_device *dev, bool want_ref);
 static inline struct neighbour *neigh_create(struct neigh_table *tbl,

net/core/neighbour.c

@@ -627,37 +627,6 @@ struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 }
 EXPORT_SYMBOL(neigh_lookup);
 
-struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
-				     const void *pkey)
-{
-	struct neighbour *n;
-	unsigned int key_len = tbl->key_len;
-	u32 hash_val;
-	struct neigh_hash_table *nht;
-
-	NEIGH_CACHE_STAT_INC(tbl, lookups);
-
-	rcu_read_lock_bh();
-	nht = rcu_dereference_bh(tbl->nht);
-	hash_val = tbl->hash(pkey, NULL, nht->hash_rnd) >> (32 - nht->hash_shift);
-
-	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
-	     n != NULL;
-	     n = rcu_dereference_bh(n->next)) {
-		if (!memcmp(n->primary_key, pkey, key_len) &&
-		    net_eq(dev_net(n->dev), net)) {
-			if (!refcount_inc_not_zero(&n->refcnt))
-				n = NULL;
-			NEIGH_CACHE_STAT_INC(tbl, hits);
-			break;
-		}
-	}
-
-	rcu_read_unlock_bh();
-	return n;
-}
-EXPORT_SYMBOL(neigh_lookup_nodev);
-
 static struct neighbour *
 ___neigh_create(struct neigh_table *tbl, const void *pkey,
 		struct net_device *dev, u32 flags,