pkt_sched: Remove comment reference to old style TX locking.

We haven't had netdev->tbusy in many years :)

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index e9ebc7a..69e918b 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -99,7 +99,7 @@
    ---requeue
 
    requeues once dequeued packet. It is used for non-standard or
-   just buggy devices, which can defer output even if dev->tbusy=0.
+   just buggy devices, which can defer output even if netif_queue_stopped()=0.
 
    ---reset