gpio: mockup: initialize a managed pointer in place

The preferred pattern for autopointers is to initialize them when they're
declared unless it doesn't make sense. Move the declaration of the
managed device pointer to where it's initialized.

Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-mockup.c

···
 static void gpio_mockup_debugfs_setup(struct device *dev,
 				      struct gpio_mockup_chip *chip)
 {
-	struct device *child __free(put_device) = NULL;
 	struct gpio_mockup_dbgfs_private *priv;
 	struct gpio_chip *gc;
 	const char *devname;
···
 	 * There can only be a single GPIO device per platform device in
 	 * gpio-mockup so using device_find_any_child() is OK.
 	 */
-	child = device_find_any_child(dev);
+	struct device *child __free(put_device) = device_find_any_child(dev);
 	if (!child)
 		return;