net: Define accessors to manipulate QDISC_STATE_RUNNING

Define three helpers to manipulate QDISC_STATE_RUNNIG flag, that a
second patch will move on another location.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 983a3c1..2733226 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2047,7 +2047,7 @@
 		kfree_skb(skb);
 		rc = NET_XMIT_DROP;
 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
-		   !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) {
+		   qdisc_run_begin(q)) {
 		/*
 		 * This is a work-conserving queue; there are no old skbs
 		 * waiting to be sent out; and the qdisc is not running -
@@ -2059,7 +2059,7 @@
 		if (sch_direct_xmit(skb, q, dev, txq, root_lock))
 			__qdisc_run(q);
 		else
-			clear_bit(__QDISC_STATE_RUNNING, &q->state);
+			qdisc_run_end(q);
 
 		rc = NET_XMIT_SUCCESS;
 	} else {