gpio: fix memory and reference leaks in gpiochip_add error path

commit 5539b3c9 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: 391c970c ("of/gpio: add default of_xlate function if device
has a node pointer")
Fixes: 664e3e5a ("gpio / ACPI: register to ACPI events
automatically")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[lizf: Backported to 3.4:
 - move the call to of_gpiochip_add() into the above if condition.
 - remove the call to acpi_gpiochip_remove()]
Signed-off-by: Zefan Li <lizefan@huawei.com>

drivers/gpio/gpiolib.c

@@ -1081,19 +1081,18 @@ int gpiochip_add(struct gpio_chip *chip)
 				? (1 << FLAG_IS_OUT)
 				: 0;
 		}
-	}
 
 		of_gpiochip_add(chip);
+	}
 
 unlock:
 	spin_unlock_irqrestore(&gpio_lock, flags);
 
-	if (status)
-		goto fail;
-
 	status = gpiochip_export(chip);
-	if (status)
+	if (status) {
+		of_gpiochip_remove(chip);
 		goto fail;
+	}
 
 	pr_info("gpiochip_add: registered GPIOs %d to %d on device: %s\n",
 		chip->base, chip->base + chip->ngpio - 1,