sch_htb: remove unnecessary NULL pointer judgment

It already has a NULL pointer judgment of rtab in qdisc_put_rtab().
Remove the judgment outside of qdisc_put_rtab().
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/sch_htb.c

@@ -1337,7 +1337,6 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 	struct htb_sched *q = qdisc_priv(sch);
 	struct htb_class *cl = (struct htb_class *)*arg, *parent;
 	struct nlattr *opt = tca[TCA_OPTIONS];
-	struct qdisc_rate_table *rtab = NULL, *ctab = NULL;
 	struct nlattr *tb[TCA_HTB_MAX + 1];
 	struct tc_htb_opt *hopt;
 	u64 rate64, ceil64;
@@ -1361,16 +1360,11 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 		goto failure;
 
 	/* Keeping backward compatible with rate_table based iproute2 tc */
-	if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE) {
-		rtab = qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB]);
-		if (rtab)
-			qdisc_put_rtab(rtab);
-	}
-	if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE) {
-		ctab = qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB]);
-		if (ctab)
-			qdisc_put_rtab(ctab);
-	}
+	if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
+		qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB]));
+
+	if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE)
+		qdisc_put_rtab(qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB]));
 
 	if (!cl) {		/* new class */
 		struct Qdisc *new_q;