core: And one more race in multithreaded mkdir -p

Sigh =(

src/libotutil/ot-gio-utils.c

@@ -72,7 +72,7 @@ ot_gfile_ensure_directory (GFile     *dir,
               if (!ot_gfile_ensure_directory (parent, TRUE, error))
                 goto out;
             }
-          if (!g_file_make_directory (dir, NULL, error))
+          if (!ot_gfile_ensure_directory (dir, FALSE, error))
             goto out;
         }
       else if (!g_error_matches (temp_error, G_IO_ERROR, G_IO_ERROR_EXISTS))