scsi: myrs: fix build failure on 32 bit

For 32 bit versions we have to be careful about divisions of 64 bit
quantities so use do_div() instead of a direct division.  This fixes a
warning about _uldivmod being undefined in certain configurations

Fixes: 77266186397c ("scsi: myrs: Add Mylex RAID controller")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/myrs.c

@@ -1978,7 +1978,8 @@ myrs_get_resync(struct device *dev)
 	struct scsi_device *sdev = to_scsi_device(dev);
 	struct myrs_hba *cs = shost_priv(sdev->host);
 	struct myrs_ldev_info *ldev_info = sdev->hostdata;
-	u8 percent_complete = 0, status;
+	u64 percent_complete = 0;
+	u8 status;
 
 	if (sdev->channel < cs->ctlr_info->physchan_present || !ldev_info)
 		return;
@@ -1986,8 +1987,8 @@ myrs_get_resync(struct device *dev)
 		unsigned short ldev_num = ldev_info->ldev_num;
 
 		status = myrs_get_ldev_info(cs, ldev_num, ldev_info);
-		percent_complete = ldev_info->rbld_lba * 100 /
-			ldev_info->cfg_devsize;
+		percent_complete = ldev_info->rbld_lba * 100;
+		do_div(percent_complete, ldev_info->cfg_devsize);
 	}
 	raid_set_resync(myrs_raid_template, dev, percent_complete);
 }