Replace some hsprintf() by phutil_tag()

Test Plan: Looked at a diff with inline comment.

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7549

src/applications/differential/controller/DifferentialDiffViewController.php

@@ -36,8 +36,9 @@ final class DifferentialDiffViewController extends DifferentialController {
       // TODO: implement optgroup support in AphrontFormSelectControl?
       $select = array();
       $select[] = hsprintf('<optgroup label="%s">', pht('Create New Revision'));
-      $select[] = hsprintf(
-        '<option value="">%s</option>',
+      $select[] = phutil_tag(
+        'option',
+        array('value' => ''),
         pht('Create a new Revision...'));
       $select[] = hsprintf('</optgroup>');