ptp: Fix pass zero to ERR_PTR() in ptp_clock_register

mainline inclusion
from mainline-5.0-rc1
commit aea0a897af9e44c258e8ab9296fad417f1bc063a
category: bugfix
bugzilla: 6557
CVE: NA

-------------------------------------------------

Fix smatch warning:

drivers/ptp/ptp_clock.c:298 ptp_clock_register() warn:
 passing zero to 'ERR_PTR'

'err' should be set while device_create_with_groups and
pps_register_source fails

Fixes: 85a66e55 ("ptp: create "pins" together with the rest of attributes")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NZhang Dianfang <zhangdianfang@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/ptp/ptp_clock.c

@@ -253,8 +253,10 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	ptp->dev = device_create_with_groups(ptp_class, parent, ptp->devid,
 					     ptp, ptp->pin_attr_groups,
 					     "ptp%d", ptp->index);
-	if (IS_ERR(ptp->dev))
+	if (IS_ERR(ptp->dev)) {
+		err = PTR_ERR(ptp->dev);
 		goto no_device;
+	}
 
 	/* Register a new PPS source. */
 	if (info->pps) {
@@ -265,6 +267,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 		pps.owner = info->owner;
 		ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
 		if (!ptp->pps_source) {
+			err = -EINVAL;
 			pr_err("failed to register pps source\n");
 			goto no_pps;
 		}