net: ethernet: ti: am65-cpts: update ret when ptp_clock is ERROR

We always have to update the value of ret, otherwise the
 error value may be the previous one.

Fixes: f6bd5952 ("net: ethernet: ti: introduce am654 common platform time sync driver")
Signed-off-by: Wang Qing <wangqing@vivo.com>
[grygorii.strashko@ti.com: fix build warn, subj add fixes tag]
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20201112164541.3223-1-grygorii.strashko@ti.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/ti/am65-cpts.c

@@ -1001,8 +1001,7 @@ struct am65_cpts *am65_cpts_create(struct device *dev, void __iomem *regs,
 	if (IS_ERR_OR_NULL(cpts->ptp_clock)) {
 		dev_err(dev, "Failed to register ptp clk %ld\n",
 			PTR_ERR(cpts->ptp_clock));
-		if (!cpts->ptp_clock)
-			ret = -ENODEV;
+		ret = cpts->ptp_clock ? PTR_ERR(cpts->ptp_clock) : -ENODEV;
 		goto refclk_disable;
 	}
 	cpts->phc_index = ptp_clock_index(cpts->ptp_clock);