gpiolib: sysfs: Do unexport GPIO when user asks for it

It seems that sysfs interface implicitly relied on the gpiod_free() to
unexport the line. This is logically incorrect as core gpiolib should
not deal with sysfs so instead of restoring it, let's call
gpiod_unexport() from sysfs code.

Fixes: b0ce9ce4 ("gpiolib: Do not unexport GPIO on freeing")
Reported-by: Marek Behún <kabel@kernel.org>
Closes: https://lore.kernel.org/r/20230808102828.4a9eac09@dellmbSigned-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Marek Behún <kabel@kernel.org>
[Bartosz: tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpiolib-sysfs.c

@@ -515,8 +515,9 @@ static ssize_t unexport_store(const struct class *class,
 	 * they may be undone on its behalf too.
 	 */
 	if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) {
-		status = 0;
+		gpiod_unexport(desc);
 		gpiod_free(desc);
+		status = 0;
 	}
 done:
 	if (status)
@@ -781,8 +782,10 @@ void gpiochip_sysfs_unregister(struct gpio_device *gdev)
 	mutex_unlock(&sysfs_lock);
 
 	/* unregister gpiod class devices owned by sysfs */
-	for_each_gpio_desc_with_flag(chip, desc, FLAG_SYSFS)
+	for_each_gpio_desc_with_flag(chip, desc, FLAG_SYSFS) {
+		gpiod_unexport(desc);
 		gpiod_free(desc);
+	}
 }
 
 static int __init gpiolib_sysfs_init(void)