rt2x00: Minor optimizazion in txdone path

We can save an indirect function call + some instructions for fetching
the actual function pointer by passing the driver specific txwi pointer
directly from rt2800pci/rt2800usb to rt2800lib instead of using the
rt2800_drv_get_txwi callback.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
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/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index ef67f67..6a8e920 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -601,7 +601,7 @@
 }
 EXPORT_SYMBOL_GPL(rt2800_process_rxwi);
 
-void rt2800_txdone_entry(struct queue_entry *entry, u32 status)
+void rt2800_txdone_entry(struct queue_entry *entry, u32 status, __le32 *txwi)
 {
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
@@ -609,13 +609,11 @@
 	u32 word;
 	u16 mcs, real_mcs;
 	int aggr, ampdu;
-	__le32 *txwi;
 
 	/*
 	 * Obtain the status about this packet.
 	 */
 	txdesc.flags = 0;
-	txwi = rt2800_drv_get_txwi(entry);
 	rt2x00_desc_read(txwi, 0, &word);
 
 	mcs = rt2x00_get_field32(word, TXWI_W0_MCS);