null_blk: cleanup zoned mode initialization

To avoid potential compilation problems, replaced the badly written
MB_TO_SECTS() macro (missing parenthesis around the argument use) with
the inline function mb_to_sects(). And while at it, simplify the
calculation of the total number of zones of the device using the
round_up() macro.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/null_blk/zoned.c

@@ -6,7 +6,10 @@
 #define CREATE_TRACE_POINTS
 #include "trace.h"
 
-#define MB_TO_SECTS(mb) (((sector_t)mb * SZ_1M) >> SECTOR_SHIFT)
+static inline sector_t mb_to_sects(unsigned long mb)
+{
+	return ((sector_t)mb * SZ_1M) >> SECTOR_SHIFT;
+}
 
 static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
 {
@@ -77,12 +80,11 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
 		return -EINVAL;
 	}
 
-	zone_capacity_sects = MB_TO_SECTS(dev->zone_capacity);
-	dev_capacity_sects = MB_TO_SECTS(dev->size);
-	dev->zone_size_sects = MB_TO_SECTS(dev->zone_size);
-	dev->nr_zones = dev_capacity_sects >> ilog2(dev->zone_size_sects);
-	if (dev_capacity_sects & (dev->zone_size_sects - 1))
-		dev->nr_zones++;
+	zone_capacity_sects = mb_to_sects(dev->zone_capacity);
+	dev_capacity_sects = mb_to_sects(dev->size);
+	dev->zone_size_sects = mb_to_sects(dev->zone_size);
+	dev->nr_zones = round_up(dev_capacity_sects, dev->zone_size_sects)
+		>> ilog2(dev->zone_size_sects);
 
 	dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct nullb_zone),
 				    GFP_KERNEL | __GFP_ZERO);