node_types_rebuild has redundant function call

node_types_rebuild calls _node_types_build() unnecessarily, adding a slight performance overhead.

function node_types_rebuild() {
  _node_types_build();

  $node_types = node_get_types('types', NULL, TRUE);

It's redundant because node_get_types already calls _node_types_build() (when the $reset parameter is true):

function node_get_types($op = 'types', $node = NULL, $reset = FALSE) {
  static $_node_types, $_node_names;

  if ($reset || !isset($_node_types)) {
    list($_node_types, $_node_names) = _node_types_build();
  }