Some doc blocks should use bool instead of true|false

See #32444.


git-svn-id: https://develop.svn.wordpress.org/trunk@32963 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/vars.php

@@ -120,7 +120,7 @@ $is_iis7 = $is_IIS && intval( substr( $_SERVER['SERVER_SOFTWARE'], strpos( $_SER
  *
  * @staticvar bool $is_mobile
  *
- * @return bool true|false
+ * @return bool
  */
 function wp_is_mobile() {
 	static $is_mobile = null;