gpio: cdev: Fix resource leaks on errors in gpiolib_cdev_register()

On error handling paths, gpiolib_cdev_register() doesn't free the
allocated resources which results leaks.  Fix it.

Cc: stable@vger.kernel.org
Fixes: 7b9b77a ("gpiolib: add a per-gpio_device line state notification workqueue")
Fixes: d83cee3 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20260120092650.2305319-1-tzungbi@kernel.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Author: Tzung-Bi Shih

drivers/gpio/gpiolib-cdev.c

@@ -2797,13 +2797,18 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
 		return -ENOMEM;
 
 	ret = cdev_device_add(&gdev->chrdev, &gdev->dev);
-	if (ret)
+	if (ret) {
+		destroy_workqueue(gdev->line_state_wq);
 		return ret;
+	}
 
 	guard(srcu)(&gdev->srcu);
 	gc = srcu_dereference(gdev->chip, &gdev->srcu);
-	if (!gc)
+	if (!gc) {
+		cdev_device_del(&gdev->chrdev, &gdev->dev);
+		destroy_workqueue(gdev->line_state_wq);
 		return -ENODEV;
+	}
 
 	gpiochip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id);