scsi: scsi_debug: Avoid PI being disabled when TPGS is enabled

It was not possible to enable both T10 PI and TPGS because they share
the same byte in the INQUIRY response. Logically OR the TPGS value
instead of using assignment.
Reported-by: NRitika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_debug.c

@@ -1404,7 +1404,7 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 	arr[4] = SDEBUG_LONG_INQ_SZ - 5;
 	arr[5] = (int)have_dif_prot;	/* PROTECT bit */
 	if (sdebug_vpd_use_hostno == 0)
-		arr[5] = 0x10; /* claim: implicit TGPS */
+		arr[5] |= 0x10; /* claim: implicit TPGS */
 	arr[6] = 0x10; /* claim: MultiP */
 	/* arr[6] |= 0x40; ... claim: EncServ (enclosure services) */
 	arr[7] = 0xa; /* claim: LINKED + CMDQUE */