gpio: of: Fix of_gpiochip_add() error path

If the call to of_gpiochip_scan_gpios() in of_gpiochip_add() fails, no
error handling is performed.  This lead to the need of callers to call
of_gpiochip_remove() on failure, which causes "BAD of_node_put() on ..."
if the failure happened before the call to of_node_get().

Fix this by adding proper error handling.

Note that calling gpiochip_remove_pin_ranges() multiple times causes no
harm: subsequent calls are a no-op.

Fixes: dfbd379 ("gpio: of: Return error if gpio hog configuration failed")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib-of.c

@@ -718,7 +718,13 @@ int of_gpiochip_add(struct gpio_chip *chip)
 
 	of_node_get(chip->of_node);
 
-	return of_gpiochip_scan_gpios(chip);
+	status = of_gpiochip_scan_gpios(chip);
+	if (status) {
+		of_node_put(chip->of_node);
+		gpiochip_remove_pin_ranges(chip);
+	}
+
+	return status;
 }
 
 void of_gpiochip_remove(struct gpio_chip *chip)