net: sched: drop all special handling of tx_queue_len == 0

Those were all workarounds for the formerly double meaning of
tx_queue_len, which broke scheduling algorithms if untreated.

Now that all in-tree drivers have been converted away from setting
tx_queue_len = 0, it should be safe to drop these workarounds for
categorically broken setups.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index abb9f2f..8010510 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -512,11 +512,9 @@
 
 	if (tb[TCA_GRED_LIMIT])
 		sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
-	else {
-		u32 qlen = qdisc_dev(sch)->tx_queue_len ? : 1;
-
-		sch->limit = qlen * psched_mtu(qdisc_dev(sch));
-	}
+	else
+		sch->limit = qdisc_dev(sch)->tx_queue_len
+		             * psched_mtu(qdisc_dev(sch));
 
 	return gred_change_table_def(sch, tb[TCA_GRED_DPS]);
 }