rt2x00: Request usb_maxpacket() once

The usb max packet size won't change during the
device's presence. We should store it in a
variable inside rt2x00dev and use that.
This should also fix a division error when the
device is being hot-unplugged while a frame is
being send out.

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 277a020..50775f9 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1032,7 +1032,7 @@
 }
 
 static int rt2500usb_get_tx_data_len(struct rt2x00_dev *rt2x00dev,
-				     int maxpacket, struct sk_buff *skb)
+				     struct sk_buff *skb)
 {
 	int length;
 
@@ -1041,7 +1041,7 @@
 	 * but it must _not_ be a multiple of the USB packet size.
 	 */
 	length = roundup(skb->len, 2);
-	length += (2 * !(length % maxpacket));
+	length += (2 * !(length % rt2x00dev->usb_maxpacket));
 
 	return length;
 }
@@ -1643,7 +1643,6 @@
 	struct data_entry *beacon;
 	struct data_entry *guardian;
 	int pipe = usb_sndbulkpipe(usb_dev, 1);
-	int max_packet = usb_maxpacket(usb_dev, pipe, 1);
 	int length;
 
 	/*
@@ -1672,7 +1671,7 @@
 							 ring->desc_size),
 				skb->len - ring->desc_size, control);
 
-	length = rt2500usb_get_tx_data_len(rt2x00dev, max_packet, skb);
+	length = rt2500usb_get_tx_data_len(rt2x00dev, skb);
 
 	usb_fill_bulk_urb(beacon->priv, usb_dev, pipe,
 			  skb->data, length, rt2500usb_beacondone, beacon);