Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index b8452cc..2be8d6b 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -72,7 +72,6 @@ struct neigh_parms {
 	struct net_device *dev;
 	struct list_head list;
 	int	(*neigh_setup)(struct neighbour *);
-	void	(*neigh_cleanup)(struct neighbour *);
 	struct neigh_table *tbl;
 
 	void	*sysctl_table;
@@ -205,6 +204,7 @@ struct neigh_table {
 	int			(*pconstructor)(struct pneigh_entry *);
 	void			(*pdestructor)(struct pneigh_entry *);
 	void			(*proxy_redo)(struct sk_buff *skb);
+	int			(*is_multicast)(const void *pkey);
 	bool			(*allow_add)(const struct net_device *dev,
 					     struct netlink_ext_ack *extack);
 	char			*id;
@@ -468,7 +468,7 @@ static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb
 
 	do {
 		seq = read_seqbegin(&hh->hh_lock);
-		hh_len = hh->hh_len;
+		hh_len = READ_ONCE(hh->hh_len);
 		if (likely(hh_len <= HH_DATA_MOD)) {
 			hh_alen = HH_DATA_MOD;