net: sched: pie: change tc_pie_xstats->prob

Commit 105e808c ("pie: remove pie_vars->accu_prob_overflows")
changes the scale of probability values in PIE from (2^64 - 1) to
(2^56 - 1). This affects the precision of tc_pie_xstats->prob in
user space.

This patch ensures user space is unaffected.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_pie.c

@@ -493,7 +493,7 @@ static int pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 {
 	struct pie_sched_data *q = qdisc_priv(sch);
 	struct tc_pie_xstats st = {
-		.prob		= q->vars.prob,
+		.prob		= q->vars.prob << BITS_PER_BYTE,
 		.delay		= ((u32)PSCHED_TICKS2NS(q->vars.qdelay)) /
 				   NSEC_PER_USEC,
 		.packets_in	= q->stats.packets_in,