net: dsa: mv88e6xxx: use gpio get optional variant

Use the optional variant to get the reset GPIO line, instead of checking
for the -ENOENT error.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx.c

@@ -3744,16 +3744,9 @@ static int mv88e6xxx_probe(struct mdio_device *mdiodev)
 	if (!ps->info)
 		return -ENODEV;
 
-	ps->reset = devm_gpiod_get(dev, "reset", GPIOD_ASIS);
-	if (IS_ERR(ps->reset)) {
-		err = PTR_ERR(ps->reset);
-		if (err == -ENOENT) {
-			/* Optional, so not an error */
-			ps->reset = NULL;
-		} else {
-			return err;
-		}
-	}
+	ps->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_ASIS);
+	if (IS_ERR(ps->reset))
+		return PTR_ERR(ps->reset);
 
 	if (mv88e6xxx_has(ps, MV88E6XXX_FLAG_EEPROM) &&
 	    !of_property_read_u32(np, "eeprom-length", &eeprom_len))