[SCSI] scsi_debug: simplify offset calculation for dif_storep
[SCSI] scsi_debug: simplify offset calculation for dif_storep

dif_storep is declared as pointer to unsigned char type.  But it is
actually used to store vmalloced array of struct sd_dif_tuple.

This changes the type of dif_storep to the pointer to struct sd_dif_tuple.
It simplifies offset calculation for dif_storep and enables to remove
hardcoded size of struct sd_dif_tuple.

Signed-off-by: Akinobu Mita <3807cf899f217da549814bf6c330d3b6e6819ccf@gmail.com>
Acked-by: Douglas Gilbert <54dff2264884c355ed5584a3b7f1530b4b26921e@interlog.com>
Acked-by: "Martin K. Petersen" <0384aaef27f06874adbdb09a807bb339f4aff9fd@oracle.com>
Signed-off-by: James Bottomley <1acebbdca565c7b6b638bdc23b58b5610d1a56b8@Parallels.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs