rt2x00usb: Fix a warning message in 'rt2x00usb_watchdog_tx_dma()'

'forced' is duplicated in the message, axe one of them.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ralink/rt2x00/rt2x00usb.c

@@ -522,7 +522,7 @@ EXPORT_SYMBOL_GPL(rt2x00usb_flush_queue);
 
 static void rt2x00usb_watchdog_tx_dma(struct data_queue *queue)
 {
-	rt2x00_warn(queue->rt2x00dev, "TX queue %d DMA timed out, invoke forced forced reset\n",
+	rt2x00_warn(queue->rt2x00dev, "TX queue %d DMA timed out, invoke forced reset\n",
 		    queue->qid);
 
 	rt2x00queue_stop_queue(queue);