Term merge AJAX error - Call to term_merge() is incorrect according to docs

The call to term_merge() doesn't follow the interface requirements and causes a patched version to fail. See this issue at Term Merge - http://drupal.org/node/1160612

Following this is a patch. The docs for the term_merge() function:

/**
 *  Merge source terms into one destination term.
 * @param $source
 *    A single term tid or an array of term tids to be merged.
 * @param $dest
 *    The tid of the term to merge sources into.
 */
function term_merge($source, $dest, $keep_merged) {

The call to term_merge() passes the term object when it should just be the id.