net: smc91x: make use of 4th parameter to devm_gpiod_get_index

Since 39b2bbe3 (gpio: add flags argument to gpiod_get*() functions)
which appeared in v3.17-rc1, the gpiod_get* functions take an additional
parameter that allows to specify direction and initial value for output.
Simplify accordingly.

Moreover use devm_gpiod_get_index_optional for still simpler handling.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/smsc/smc91x.c

@@ -2204,27 +2204,18 @@ static int try_toggle_control_gpio(struct device *dev,
 				   int value, unsigned int nsdelay)
 {
 	struct gpio_desc *gpio = *desc;
+	enum gpiod_flags flags = value ? GPIOD_OUT_LOW : GPIOD_OUT_HIGH;
 	int res;
 
-	gpio = devm_gpiod_get_index(dev, name, index);
-	if (IS_ERR(gpio)) {
-		if (PTR_ERR(gpio) == -ENOENT) {
-			*desc = NULL;
-			return 0;
-		}
-
+	gpio = devm_gpiod_get_index_optional(dev, name, index, flags);
+	if (IS_ERR(gpio))
 		return PTR_ERR(gpio);
-	}
-	res = gpiod_direction_output(gpio, !value);
-	if (res) {
-		dev_err(dev, "unable to toggle gpio %s: %i\n", name, res);
-		devm_gpiod_put(dev, gpio);
-		gpio = NULL;
-		return res;
-	}
+
+	if (gpio) {
 		if (nsdelay)
 			usleep_range(nsdelay, 2 * nsdelay);
 		gpiod_set_value_cansleep(gpio, value);
+	}
 	*desc = gpio;
 
 	return 0;