scsi: sd: Unregister device if device_add_disk() failed in sd_probe()

"if device_add() succeeds, you should call device_del() when you want to
get rid of it."

In sd_probe(), device_add_disk() fails when device_add() has already
succeeded, so change put_device() to device_unregister() to ensure device
resources are released.

Fixes: 2a7a891f ("scsi: sd: Add error handling support for add_disk()")
Signed-off-by: Li Nan <linan122@huawei.com>
Link: https://lore.kernel.org/r/20231208082335.1754205-1-linan666@huaweicloud.com


Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>