net_sched: fix struct tc_u_hnode layout in u32

net_sched: fix struct tc_u_hnode layout in u32

We dynamically allocate divisor+1 entries for ->ht[] in tc_u_hnode:

  ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);

So ->ht is supposed to be the last field of this struct, however
this is broken, since an rcu head is appended after it.

Fixes: 1ce87720d456 ("net: sched: make cls_u32 lockless")
Cc: Jamal Hadi Salim <[email protected]>
Cc: John Fastabend <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Acked-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>