net: gianfar: remove the unneeded check of disabled device

Since commit cd1e6504 ("of/device: Don't register disabled
devices"), the disabled device will not be registered at all. So we
don't need to do the check again in the platform device driver.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/gianfar.c

@@ -764,7 +764,7 @@ static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 	u32 *tx_queues, *rx_queues;
 	unsigned short mode, poll_mode;
 
-	if (!np || !of_device_is_available(np))
+	if (!np)
 		return -ENODEV;
 
 	if (of_device_is_compatible(np, "fsl,etsec2")) {