scsi: scsi_debug: Add debugfs interface to fail target reset

The interface is found at
/sys/kernel/debug/scsi_debug/target<h:c:t>/fail_reset where <h:c:t>
identifies the target to inject errors on. It's a simple bool type
interface which would make this target's reset fail if set to 'Y'.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-10-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>