rt2x00: Always call ieee80211_stop_queue() when return NETDEV_TX_BUSY

Apparently it was possible that ieee80211_stop_queue() was not full while
NETDEV_TX_BUSY was being reported back. I think that is what causing the WARN_ON().
This moves all calls to ieee80211_stop_queue() in rt2x00mac.c where it is easier
to determine if the queue should be halted.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 9778fae..fa0cdd8 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -179,17 +179,14 @@
 	struct skb_desc *desc;
 	u32 length;
 
-	if (rt2x00_ring_full(ring)) {
-		ieee80211_stop_queue(rt2x00dev->hw, control->queue);
+	if (rt2x00_ring_full(ring))
 		return -EINVAL;
-	}
 
 	if (test_bit(ENTRY_OWNER_NIC, &entry->flags)) {
 		ERROR(rt2x00dev,
 		      "Arrived at non-free entry in the non-full queue %d.\n"
 		      "Please file bug report to %s.\n",
 		      control->queue, DRV_PROJECT);
-		ieee80211_stop_queue(rt2x00dev->hw, control->queue);
 		return -EINVAL;
 	}
 
@@ -229,9 +226,6 @@
 
 	rt2x00_ring_index_inc(ring);
 
-	if (rt2x00_ring_full(ring))
-		ieee80211_stop_queue(rt2x00dev->hw, control->queue);
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);