scsi: core: Add kunit tests for scsi_check_passthrough()

Add some kunit tests for scsi_check_passthrough() so we can easily make
sure we are hitting the cases for which it's difficult to replicate in
hardware or even scsi_debug.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-20-michael.christie@oracle.com
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>