net_sched: gred: eliminate redundant DP prio comparisons

Each pair of DPs only needs to be compared once when searching for
a non-unique prio value.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_gred.c

@@ -102,9 +102,8 @@ static inline int gred_wred_mode_check(struct Qdisc *sch)
 		if (q == NULL)
 			continue;
 
-		for (n = 0; n < table->DPs; n++)
-			if (table->tab[n] && table->tab[n] != q &&
-			    table->tab[n]->prio == q->prio)
+		for (n = i + 1; n < table->DPs; n++)
+			if (table->tab[n] && table->tab[n]->prio == q->prio)
 				return 1;
 	}