Bluetooth: hci_h4: Remove a redundant assignment in 'h4_flush()'

'hu->priv' is set twice to NULL in this function.
Axe one of these assignments.

Signed-off-by: Christophe JAILLET <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

drivers/bluetooth/hci_h4.c

···
 {
 	struct h4_struct *h4 = hu->priv;
 
-	hu->priv = NULL;
-
 	BT_DBG("hu %p", hu);
 
 	skb_queue_purge(&h4->txq);