scsi: sd_zbc: Support disks with more than 2**32 logical blocks

This patch addresses the following Coverity report about the zno *
sdkp->zone_blocks expression:

CID 1475514 (#1 of 1): Unintentional integer overflow (OVERFLOW_BEFORE_WIDEN)
overflow_before_widen: Potentially overflowing expression zno *
sdkp->zone_blocks with type unsigned int (32 bits, unsigned) is evaluated
using 32-bit arithmetic, and then used in a context that expects an
expression of type sector_t (64 bits, unsigned).

Link: https://lore.kernel.org/r/20210917212314.2362324-1-bvanassche@acm.org
Fixes: 5795eb44 ("scsi: sd_zbc: emulate ZONE_APPEND commands")
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/sd_zbc.c

@@ -280,7 +280,7 @@ static void sd_zbc_update_wp_offset_workfn(struct work_struct *work)
 {
 	struct scsi_disk *sdkp;
 	unsigned long flags;
-	unsigned int zno;
+	sector_t zno;
 	int ret;
 
 	sdkp = container_of(work, struct scsi_disk, zone_wp_offset_work);