pm8001: Fix erratic calculation in update_flash

The loopcount is calculated by using some weird magic. Use instead a boring
macro.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Acked-by: Suresh Thiagarajan <Suresh.Thiagarajan@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/pm8001/pm8001_ctl.c b/drivers/scsi/pm8001/pm8001_ctl.c
index d3a08ae..e9b0921 100644
--- a/drivers/scsi/pm8001/pm8001_ctl.c
+++ b/drivers/scsi/pm8001/pm8001_ctl.c
@@ -581,11 +581,8 @@
 		partitionSizeTmp =
 			*(u32 *)((u8 *)&image_hdr->image_length + sizeRead);
 		partitionSize = be32_to_cpu(partitionSizeTmp);
-		loopcount = (partitionSize + HEADER_LEN)/IOCTL_BUF_SIZE;
-		if (loopcount % IOCTL_BUF_SIZE)
-			loopcount++;
-		if (loopcount == 0)
-			loopcount++;
+		loopcount = DIV_ROUND_UP(partitionSize + HEADER_LEN,
+					IOCTL_BUF_SIZE);
 		for (loopNumber = 0; loopNumber < loopcount; loopNumber++) {
 			payload = (struct pm8001_ioctl_payload *)ioctlbuffer;
 			payload->length = 1024*16;