rt2x00: Implement rt2x00usb_kick_tx_queue()

rt2x00usb_kick_tx_queue() will loop over all entries
within the INDEX_DONE->INDEX range and kick each entry
which is pending to be kicked. This makes the kick_tx_queue
approach work the same as with the PCI drivers which
will allow for more code generalisation into rt2x00lib.

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/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index 0d51b74..6abb4c5 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1116,8 +1116,10 @@
 {
 	u16 reg;
 
-	if (queue != QID_BEACON)
+	if (queue != QID_BEACON) {
+		rt2x00usb_kick_tx_queue(rt2x00dev, queue);
 		return;
+	}
 
 	rt2500usb_register_read(rt2x00dev, TXRX_CSR19, &reg);
 	if (!rt2x00_get_field16(reg, TXRX_CSR19_BEACON_GEN)) {