scsi: scsi_debug: Fix buffer size of REPORT ZONES command

According to ZBC and SPC specifications, the unit of ALLOCATION LENGTH
field of REPORT ZONES command is byte. However, current scsi_debug
implementation handles it as number of zones to calculate buffer size to
report zones. When the ALLOCATION LENGTH has a large number, this results
in too large buffer size and causes memory allocation failure.  Fix the
failure by handling ALLOCATION LENGTH as byte unit.

Link: https://lore.kernel.org/r/20211207010638.124280-1-shinichiro.kawasaki@wdc.com
Fixes: f0d1cf9378 ("scsi: scsi_debug: Add ZBC zone commands")
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_debug.c

@@ -4342,7 +4342,7 @@ static int resp_report_zones(struct scsi_cmnd *scp,
 	rep_max_zones = min((alloc_len - 64) >> ilog2(RZONES_DESC_HD),
 			    max_zones);
 
-	arr = kcalloc(RZONES_DESC_HD, alloc_len, GFP_ATOMIC);
+	arr = kzalloc(alloc_len, GFP_ATOMIC);
 	if (!arr) {
 		mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
 				INSUFF_RES_ASCQ);