[PATCH net-next] net: ethtool: cable-test: Release RTNL when the PHY isn't found

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Use the correct logic to check for the presence of a PHY device, and
jump to a label that correctly releases RTNL in case of an error, as we
are holding RTNL at that point.

Fixes: 3688ff3077d3 ("net: ethtool: cable-test: Target the command to the requested PHY")
Closes: https://lore.kernel.org/netdev/20240827104825.5cbe0602@fedora-3.home/T/#m6bc49cdcc5cfab0d162516b92916b944a01c833f
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
---

I'm targetting this patch to net-next as this is where the commit it fixes lives.

 net/ethtool/cabletest.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ethtool/cabletest.c b/net/ethtool/cabletest.c
index ff2fe3566ace..371bdc1598ce 100644
--- a/net/ethtool/cabletest.c
+++ b/net/ethtool/cabletest.c
@@ -343,9 +343,9 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info)
 	phydev = ethnl_req_get_phydev(&req_info,
 				      tb[ETHTOOL_A_CABLE_TEST_TDR_HEADER],
 				      info->extack);
-	if (!IS_ERR_OR_NULL(phydev)) {
+	if (IS_ERR_OR_NULL(phydev)) {
 		ret = -EOPNOTSUPP;
-		goto out_dev_put;
+		goto out_rtnl;
 	}
 
 	ops = ethtool_phy_ops;
-- 
2.45.2