[NET_SCHED]: Cleanup L2T macros and handle oversized packets

Change L2T (length to time) macros, in all rate based schedulers, to
call a common function qdisc_l2t() that does the rate table lookup.
This function handles if the packet size lookup is larger than the
rate table, which often occurs with TSO enabled.

Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 246a2f9..5e608a6 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -132,10 +132,8 @@
 static inline long L2T(struct htb_class *cl, struct qdisc_rate_table *rate,
 			   int size)
 {
-	int slot = size >> rate->rate.cell_log;
-	if (slot > 255)
-		return (rate->data[255]*(slot >> 8) + rate->data[slot & 0xFF]);
-	return rate->data[slot];
+	long result = qdisc_l2t(rate, size);
+	return result;
 }
 
 struct htb_sched {