Use entity_uri() to retrieve uri so that overridden callbacks are called correctly

This should be fixed in the other functions as well:
tagclouds_display_node_link_count()
tagclouds_display_term_link_count()

In Drupal 6 you could override the default url taxonomy/term/% for a specific vocabulary by setting your module's name in the vocabularies table. In Drupal 7 this no longer works that way. With the entities sytem you can override URL creation by setting the uri callback on bundle level:

/**
 * Implements hook_entity_info_alter().
 */
function mymodule_entity_info_alter(&$info) {
  $info['taxonomy_term']['bundles']['tags']['uri callback'] = 'mymodule_tags_vocabulary_uri';
}

Then, if you use entity_uri(); you get the correct callback since that first checks if a callback on bundle level exists.

I've added a patch that also uses the taxonomy API function taxonomy_term_load instead of using the callback.

The function tagclouds_display_node_link_count() should also be fixed since the signature says $nid and then $node_info is initialised with the info from taxonomy_term. So either the variables should be renamed for clarity or the wrong info is loaded.