scsi: scsi_debug: fix write_same with virtual_gb problem

The WRITE SAME(10) and (16) implementations didn't take account of the
buffer wrap required when the virtual_gb parameter is greater than 0.

Fix that and rename the fake_store() function to lba2fake_store() to lessen
confusion with the global fake_storep pointer. Bump version date.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reported-by: Bart Van Assche <bvanassche@acm.org>
Tested by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>