scsi: scsi_debug: Improve RDPROTECT/WRPROTECT handling

It is useful for testing purposes to be able to inject errors by writing
bad protection information to media with checking disabled and then
attempting to read it back. Extend scsi_debug's PI verification logic to
give the driver feature parity with commercially available drives. Almost
all devices with PI capability support RDPROTECT and WRPROTECT values of 0,
1, and 3.

Link: https://lore.kernel.org/r/20210609033929.3815-10-martin.petersen@oracle.com


Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Message-Id: <20210609033929.3815-10-martin.petersen@oracle.com>