gpiolib: Free the last requested descriptor

The current code only frees N-1 gpios if an error occurs during
gpiod_set_transitory, gpiod_direction_output or gpiod_direction_input.
Leading to gpios that cannot be used by userspace nor other drivers.

Cc: Timur Tabi <[email protected]>
Cc: [email protected]
Fixes: ab3dbcf ("gpioib: do not free unrequested descriptors)
Reported-by: Jan Lorenzen <[email protected]>
Reported-by: Jim Paris <[email protected]>
Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>

drivers/gpio/gpiolib.c

@@ -571,7 +571,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 		if (ret)
 			goto out_free_descs;
 		lh->descs[i] = desc;
-		count = i;
+		count = i + 1;
 
 		if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
 			set_bit(FLAG_ACTIVE_LOW, &desc->flags);