gpio: Convert to using %pOFn instead of device_node.name

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib-of.c

@@ -348,8 +348,8 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
 	else if (of_property_read_bool(np, "output-high"))
 		*dflags |= GPIOD_OUT_HIGH;
 	else {
-		pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
-			desc_to_gpio(desc), np->name);
+		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
+			desc_to_gpio(desc), np);
 		return ERR_PTR(-EINVAL);
 	}