BACKPORT: gpio: fix memory and reference leaks in gpiochip_add error path

commit 5539b3c938d64a60cb1fc442ac3ce9263d52de0c upstream.

Memory allocated and references taken by of_gpiochip_add and
acpi_gpiochip_add were never released on errors in gpiochip_add (e.g.
failure to find free gpio range).

Fixes: 391c970c0d ("of/gpio: add default of_xlate function if device
has a node pointer")
Fixes: 664e3e5ac64c ("gpio / ACPI: register to ACPI events
automatically")

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
[syphyr: removed references to acpi_gpiochip_remove for 3.10]
Signed-off-by: L R <syphyr@gmail.com>

drivers/gpio/gpiolib.c

@@ -1246,18 +1246,20 @@ int gpiochip_add(struct gpio_chip *chip)
 
 	spin_unlock_irqrestore(&gpio_lock, flags);
 
+	if (status)
+		goto fail;
+
 #ifdef CONFIG_PINCTRL
 	INIT_LIST_HEAD(&chip->pin_ranges);
 #endif
 
 	of_gpiochip_add(chip);
 
-	if (status)
-		goto fail;
-
 	status = gpiochip_export(chip);
-	if (status)
+	if (status) {
+		of_gpiochip_remove(chip);
 		goto fail;
+	}
 
 	pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n",
 		chip->base, chip->base + chip->ngpio - 1,