add parens around tmp_path

Author: scrogson

test/support/file_helpers.ex

@@ -13,7 +13,7 @@ defmodule Hedwig.FileHelpers do
   tailored for this test case and test.
   """
   defmacro in_tmp(fun) do
-    path = Path.join([tmp_path, "#{__CALLER__.module}", "#{elem(__CALLER__.function, 0)}"])
+    path = Path.join([tmp_path(), "#{__CALLER__.module}", "#{elem(__CALLER__.function, 0)}"])
     quote do
       path = unquote(path)
       File.rm_rf!(path)