scsi: scsi_debug: write_same: fix error report

The scsi_debug driver incorrectly suggests there is an error with the
SCSI WRITE SAME command when the number_of_logical_blocks is greater
than 1. It will also suggest there is an error when NDOB
(no data-out buffer) is set and the number_of_logical_blocks is
greater than 0. Both are valid, fix.

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