fs_enet: Don't call NAPI functions when NAPI is not used.

fs_enet_close() calls napi_disable() unconditionally. This patch skips the
call when use_napi isn't set.

Signed-off-by: Laurent Pinchart <laurentp@cse-semaphore.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c
index af869cf..940e204 100644
--- a/drivers/net/fs_enet/fs_enet-main.c
+++ b/drivers/net/fs_enet/fs_enet-main.c
@@ -835,7 +835,8 @@
 
 	netif_stop_queue(dev);
 	netif_carrier_off(dev);
-	napi_disable(&fep->napi);
+	if (fep->fpi->use_napi)
+		napi_disable(&fep->napi);
 	phy_stop(fep->phydev);
 
 	spin_lock_irqsave(&fep->lock, flags);