net/sched: fix miss init the mru in qdisc_skb_cb

The mru in the qdisc_skb_cb should be init as 0. Only defrag packets in the
act_ct will set the value.

Fixes: 038ebb1a ("net/sched: act_ct: fix miss set mru for ovs after defrag in act_ct")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/core/dev.c

@@ -3872,6 +3872,7 @@ sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
 		return skb;
 
 	/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
+	qdisc_skb_cb(skb)->mru = 0;
 	mini_qdisc_bstats_cpu_update(miniq, skb);
 
 	switch (tcf_classify(skb, miniq->filter_list, &cl_res, false)) {
@@ -4959,6 +4960,7 @@ sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
 	}
 
 	qdisc_skb_cb(skb)->pkt_len = skb->len;
+	qdisc_skb_cb(skb)->mru = 0;
 	skb->tc_at_ingress = 1;
 	mini_qdisc_bstats_cpu_update(miniq, skb);