net: fec: disable correct clk in the err path of fec_enet_clk_enable

When enable clk_ref failed, clk_ptp should be disabled rather than
clk_ref itself.
Signed-off-by: Liu Xiang <liuxiang_1999@126.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fec_main.c

@@ -1981,8 +1981,12 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
 	return 0;
 
 failed_clk_ref:
-	if (fep->clk_ref)
-		clk_disable_unprepare(fep->clk_ref);
+	if (fep->clk_ptp) {
+		mutex_lock(&fep->ptp_clk_mutex);
+		clk_disable_unprepare(fep->clk_ptp);
+		fep->ptp_clk_on = false;
+		mutex_unlock(&fep->ptp_clk_mutex);
+	}
 failed_clk_ptp:
 	if (fep->clk_enet_out)
 		clk_disable_unprepare(fep->clk_enet_out);