gianfar: fix obviously wrong #ifdef CONFIG_GFAR_NAPI placement

Erroneous #ifdef introduced by 293c8513398657f6263fcdb03c87f2760cf61be4
causing NAPI-less ethernet malfunctioning.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/gianfar.c

@@ -956,10 +956,12 @@ static int gfar_enet_open(struct net_device *dev)
 	}
 
 	err = startup_gfar(dev);
-	if (err)
+	if (err) {
 #ifdef CONFIG_GFAR_NAPI
 		napi_disable(&priv->napi);
 #endif
+		return err;
+	}
 
 	netif_start_queue(dev);