Testing revealed a problem with how the reference tag was handled for
a WRITE_INSERT operation. The SCSI_PROT_REF_CHECK flag is not set when
the controller is asked to generate the protection information
(i.e. not DIX). And as a result the initial reference tag would not be
set in the WRITE_INSERT case.

Separate handling of the REF_CHECK and REF_INCREMENT flags to align
with both the DIX spec and the MPI implementation.

Link: https://lore.kernel.org/r/20211028034202.24225-1-martin.petersen@oracle.com
Fixes: b3e2c72a ("scsi: mpt3sas: Use the proper SCSI midlayer interfaces for PI")
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>