net: pse-pd: Use EOPNOTSUPP error code instead of ENOTSUPP

ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP as reported by
checkpatch script.

Fixes: 18ff0bcd ("ethtool: add interface to interact with Ethernet Power Equipment")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://lore.kernel.org/r/20240610083426.740660-1-kory.maincent@bootlin.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/pse-pd/pse.h

@@ -167,14 +167,14 @@ static inline int pse_ethtool_get_status(struct pse_control *psec,
 					 struct netlink_ext_ack *extack,
 					 struct pse_control_status *status)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 static inline int pse_ethtool_set_config(struct pse_control *psec,
 					 struct netlink_ext_ack *extack,
 					 const struct pse_control_config *config)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 static inline bool pse_has_podl(struct pse_control *psec)