drivers: mcb: fix resource leak in mcb_probe()

When probe hook function failed in mcb_probe(), it doesn't put the device.
Compiled test only.

Fixes: 7bc36409

 ("mcb: Acquire reference to device in probe")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Link: https://lore.kernel.org/r/9f87de36bfb85158b506cb78c6fc9db3f6a3bad1.1669624063.git.johannes.thumshirn@wdc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>