pkt_sched: Add qdisc_reset_all_tx().

Isolate callers that want to simply reset all the TX qdiscs from the
details of TX queues.

Use this in the ISDN code.
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/i4l/isdn_net.c

@@ -287,7 +287,7 @@ isdn_net_unbind_channel(isdn_net_local * lp)
 		   BEWARE! This chunk of code cannot be called from hardware
 		   interrupt handler. I hope it is true. --ANK
 		 */
-		qdisc_reset(lp->netdev->dev->tx_queue.qdisc);
+		qdisc_reset_all_tx(lp->netdev->dev);
 	}
 	lp->dialstate = 0;
 	dev->rx_netdev[isdn_dc2minor(lp->isdn_device, lp->isdn_channel)] = NULL;

include/net/sch_generic.h

@@ -227,6 +227,12 @@ extern struct Qdisc *qdisc_create_dflt(struct net_device *dev,
 extern void tcf_destroy(struct tcf_proto *tp);
 extern void tcf_destroy_chain(struct tcf_proto **fl);
 
+/* Reset all TX qdiscs of a device.  */
+static inline void qdisc_reset_all_tx(struct net_device *dev)
+{
+	qdisc_reset(dev->tx_queue.qdisc);
+}
+
 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
 				       struct sk_buff_head *list)
 {