rt2x00: Properly reserve room for descriptors in skbs.

Instead of fiddling with the skb->data pointer and thereby risking
out of bounds accesses, properly reserve the space needed in an
skb for descriptors.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 25cc376..5e12351 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -198,6 +198,11 @@
 		return;
 
 	/*
+	 * Remove the descriptor from the front of the skb.
+	 */
+	skb_pull(entry->skb, entry->queue->desc_size);
+
+	/*
 	 * Obtain the status about this packet.
 	 * Note that when the status is 0 it does not mean the
 	 * frame was send out correctly. It only means the frame
@@ -243,12 +248,6 @@
 			  rt2x00usb_interrupt_txdone, entry);
 
 	/*
-	 * Make sure the skb->data pointer points to the frame, not the
-	 * descriptor.
-	 */
-	skb_pull(entry->skb, entry->queue->desc_size);
-
-	/*
 	 * Call the driver's write_tx_datadesc function, if it exists.
 	 */
 	if (rt2x00dev->ops->lib->write_tx_datadesc)