scoutfs: deletion items maintain counts

When we turned existing items into deletion items we'd remove their
values.  But we didn't update the count of dirty values to reflect that
removal so the dirty value count would slowly grow without bound.

Signed-off-by: Zach Brown <zab@versity.com>

kmod/src/item.c

@@ -354,6 +354,7 @@ static void become_deletion_item(struct super_block *sb,
 				 struct cached_item *item,
 				 struct kvec *del_val)
 {
+	clear_item_dirty(cac, item);
 	scoutfs_kvec_clone(del_val, item->val);
 	scoutfs_kvec_init_null(item->val);
 	item->deletion = 1;