rapidio: devices: fix missing put_device in mport_cdev_open

When kfifo_alloc fails, the refcount of chdev->dev is left incremental. 
We should use put_device(&chdev->dev) to decrease the ref count of
chdev->dev to avoid refcount leak.

Link: https://lkml.kernel.org/r/20221203085721.13146-1-caixinchen1@huawei.com


Fixes: e8de3701 ("rapidio: add mport char device driver")
Signed-off-by: Cai Xinchen <caixinchen1@huawei.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>