bpf, devmap: Remove unused dtab field from bpf_dtab_netdev

Commit 96360004 ("xdp: Make devmap flush_list common for all map
instances") removes the use of bpf_dtab_netdev::dtab in bq_enqueue(),
so just remove dtab from bpf_dtab_netdev.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/20230728014942.892272-3-houtao@huaweicloud.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

kernel/bpf/devmap.c

@@ -65,7 +65,6 @@ struct xdp_dev_bulk_queue {
 struct bpf_dtab_netdev {
 	struct net_device *dev; /* must be first member, due to tracepoint */
 	struct hlist_node index_hlist;
-	struct bpf_dtab *dtab;
 	struct bpf_prog *xdp_prog;
 	struct rcu_head rcu;
 	unsigned int idx;
@@ -874,7 +873,6 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
 	}
 
 	dev->idx = idx;
-	dev->dtab = dtab;
 	if (prog) {
 		dev->xdp_prog = prog;
 		dev->val.bpf_prog.id = prog->aux->id;