Remove inaccurate comment.
diff --git a/flattree.c b/flattree.c
index 6d08c41..dd6bc1d 100644
--- a/flattree.c
+++ b/flattree.c
@@ -229,7 +229,7 @@
 	}
 
 	*d = data_append_data(*d, str, strlen(str)+1);
-	return i; /* i equals the old data length */
+	return i;
 }
 
 static void flatten_tree(struct node *tree, struct emitter *emit,