exfat-tools: fix wrong bitmap_byte_len and ut_byte_len

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
diff --git a/mkfs/mkfs.c b/mkfs/mkfs.c
index 98c0fae..46ff081 100644
--- a/mkfs/mkfs.c
+++ b/mkfs/mkfs.c
@@ -362,11 +362,10 @@
 		DEFAULT_CLUSTER_SIZE);
 	finfo.total_clu_cnt = (bd->size - finfo.clu_byte_off) / ui->cluster_size;
 	finfo.bitmap_byte_off = EXFAT_REVERVED_CLUSTERS * ui->cluster_size;
-	finfo.bitmap_byte_len =
-		round_up((bd->num_clusters / 8) , ui->cluster_size);
+	finfo.bitmap_byte_len = round_up(finfo.total_clu_cnt, 8) / 8;
 	finfo.ut_byte_off = finfo.bitmap_byte_off + finfo.bitmap_byte_len;
 	finfo.ut_start_clu = finfo.ut_byte_off / ui->cluster_size;
-	finfo.ut_byte_len = round_up(EXFAT_UPCASE_TABLE_SIZE, ui->cluster_size);
+	finfo.ut_byte_len = EXFAT_UPCASE_TABLE_SIZE;
 	finfo.root_byte_off = finfo.ut_byte_off + finfo.ut_byte_len;
 	finfo.root_start_clu = finfo.root_byte_off / ui->cluster_size;
 	finfo.root_byte_len = sizeof(struct exfat_dentry) * 3;