gianfar: Fix build.

Reported by Michael Guntsche <mike@it-loops.com>

--------------------
Commit
38bddf04bcfe661fbdab94888c3b72c32f6873b3 gianfar: gfar_remove needs to call unregister_netdev()

breaks the build of the gianfar driver because "dev" is undefined in
this function. To quickly test rc9 I changed this to priv->ndev but I do
not know if this is the correct one.
--------------------

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 24f7ca5..a00ec63 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -491,7 +491,7 @@
 
 	dev_set_drvdata(&ofdev->dev, NULL);
 
-	unregister_netdev(dev);
+	unregister_netdev(priv->ndev);
 	iounmap(priv->regs);
 	free_netdev(priv->ndev);