net_sched: sch_mqprio: dont leak kernel memory

mqprio_dump() should make sure all fields of struct tc_mqprio_qopt are
initialized.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_mqprio.c

@@ -215,7 +215,7 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 	struct net_device *dev = qdisc_dev(sch);
 	struct mqprio_sched *priv = qdisc_priv(sch);
 	unsigned char *b = skb_tail_pointer(skb);
-	struct tc_mqprio_qopt opt;
+	struct tc_mqprio_qopt opt = { 0 };
 	struct Qdisc *qdisc;
 	unsigned int i;