net: sched: gred: remove NULL check before free table->tab in gred_destroy()

The kfree invoked by gred_destroy_vq checks whether the input parameter
is empty. Therefore, gred_destroy() doesn't need to check table->tab.
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://lore.kernel.org/r/20220831041452.33026-1-shaozhengchao@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

net/sched/sch_gred.c

@@ -908,10 +908,9 @@ static void gred_destroy(struct Qdisc *sch)
 	struct gred_sched *table = qdisc_priv(sch);
 	int i;
 
-	for (i = 0; i < table->DPs; i++) {
-		if (table->tab[i])
-			gred_destroy_vq(table->tab[i]);
-	}
+	for (i = 0; i < table->DPs; i++)
+		gred_destroy_vq(table->tab[i]);
+
 	gred_offload(sch, TC_GRED_DESTROY);
 	kfree(table->opt);
 }