gianfar: Cleanup compile warning caused by 0795af57

Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 2b758fa..1509950 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -168,7 +168,6 @@
 	struct gfar_private *priv = NULL;
 	struct gianfar_platform_data *einfo;
 	struct resource *r;
-	int idx;
 	int err = 0;
 	DECLARE_MAC_BUF(mac);