btrfs: cleanup, use correct type in div_u64_rem

div_u64_rem expects u32 for divisior and reminder.

Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index c21581e..0d14146 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2318,7 +2318,7 @@
 				       unsigned long *bitmap,
 				       u64 start, u64 len)
 {
-	int offset;
+	u32 offset;
 	int nsectors;
 	int sectorsize = sparity->sctx->dev_root->sectorsize;
 
@@ -2611,8 +2611,8 @@
 	int j = 0;
 	u64 stripe_nr;
 	u64 last_offset;
-	int stripe_index;
-	int rot;
+	u32 stripe_index;
+	u32 rot;
 
 	last_offset = (physical - map->stripes[num].physical) *
 		      nr_data_stripes(map);