net: prepare usb net drivers for addition of status as a parameter

USB is going to switch the signature of the callbacks to
void callback(struct urb *urb, int status)
This patch will ease the transition.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/dm9601.c b/drivers/net/usb/dm9601.c
index db3377d..edd244f 100644
--- a/drivers/net/usb/dm9601.c
+++ b/drivers/net/usb/dm9601.c
@@ -123,10 +123,11 @@
 static void dm_write_async_callback(struct urb *urb)
 {
 	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
+	int status = urb->status;
 
-	if (urb->status < 0)
+	if (status < 0)
 		printk(KERN_DEBUG "dm_write_async_callback() failed with %d\n",
-		       urb->status);
+		       status);
 
 	kfree(req);
 	usb_free_urb(urb);