Changed off_t to loff_t

- off_t is long, loff_t is long long (32bit vs. 64bit)
- exfat requites 64 bit to support larger than 2GB fs

Change-Id: I70293e45d7d6686317edc759092e738a2ebdd860
diff --git a/exfat/libexfat/utils.c b/exfat/libexfat/utils.c
index 388f360..39d708e 100644
--- a/exfat/libexfat/utils.c
+++ b/exfat/libexfat/utils.c
@@ -161,8 +161,8 @@
 		uint32_t free_clusters)
 {
 	struct exfat_human_bytes hb;
-	off_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
-	off_t avail_space = (off_t) free_clusters * CLUSTER_SIZE(*sb);
+	loff_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
+	loff_t avail_space = (loff_t) free_clusters * CLUSTER_SIZE(*sb);
 
 	printf("File system version           %hhu.%hhu\n",
 			sb->version.major, sb->version.minor);