hrtimer: convert net::sched_cbq to the new hrtimer apis

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts sched_cbq to these accessors.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

net/sched/sch_cbq.c

@@ -545,9 +545,10 @@ static void cbq_ovl_delay(struct cbq_class *cl)
 			expires = ktime_set(0, 0);
 			expires = ktime_add_ns(expires, PSCHED_US2NS(sched));
 			if (hrtimer_try_to_cancel(&q->delay_timer) &&
-			    ktime_to_ns(ktime_sub(q->delay_timer.expires,
-						  expires)) > 0)
-				q->delay_timer.expires = expires;
+			    ktime_to_ns(ktime_sub(
+					hrtimer_get_expires(&q->delay_timer),
+					expires)) > 0)
+				hrtimer_set_expires(&q->delay_timer, expires);
 			hrtimer_restart(&q->delay_timer);
 			cl->delayed = 1;
 			cl->xstats.overactions++;