gpio: fixes for gpio-hog support

recently added gpio hog patch was "in discussion"
state with Simon Glass. This patch now adds most
of comments from Simon Glass.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/doc/device-tree-bindings/gpio/gpio.txt b/doc/device-tree-bindings/gpio/gpio.txt
index e774439..e146917 100644
--- a/doc/device-tree-bindings/gpio/gpio.txt
+++ b/doc/device-tree-bindings/gpio/gpio.txt
@@ -252,6 +252,7 @@
                 boot_rescue {
                         gpio-hog;
                         input;
+                        line-name = "foo-bar-gpio";
                         gpios = <7 GPIO_ACTIVE_LOW>;
                 };
         };
@@ -259,9 +260,13 @@
 For the above Example you can than access the gpio in your boardcode
 with:
 
-        desc = gpio_hog_lookup_name("boot_rescue.gpio-hog");
-        if (desc) {
-                if (dm_gpio_get_value(desc))
-                        printf("\nBooting into Rescue System\n");
-		else
-			printf("\nBoot normal\n");
+	struct gpio_desc *desc;
+	int ret;
+
+	ret = gpio_hog_lookup_name("boot_rescue", &desc);
+	if (ret)
+		return;
+	if (dm_gpio_get_value(desc) == 1)
+		printf("\nBooting into Rescue System\n");
+	else if (dm_gpio_get_value(desc) == 0)
+		printf("\nBoot normal\n");