siox: fix possible memory leak in siox_device_add()

If device_register() returns error in siox_device_add(),
the name allocated by dev_set_name() need be freed. As
comment of device_register() says, it should use put_device()
to give up the reference in the error path. So fix this
by calling put_device(), then the name can be freed in
kobject_cleanup(), and sdevice is freed in siox_device_release(),
set it to null in error path.

Fixes: bbecb07fa0 ("siox: new driver framework for eckelmann SIOX")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221104021334.618189-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/siox/siox-core.c

@@ -839,6 +839,8 @@ static struct siox_device *siox_device_add(struct siox_master *smaster,
 
 err_device_register:
 	/* don't care to make the buffer smaller again */
+	put_device(&sdevice->dev);
+	sdevice = NULL;
 
 err_buf_alloc:
 	siox_master_unlock(smaster);