MDL-77164 lib/pear: correct phpdocs

lib/pear/HTML/Common.php

@@ -274,7 +274,7 @@ class HTML_Common {
      * @param     string    $attr   Attribute name
      * @since     1.5
      * @access    public
-     * @return    void
+     * @return    mixed
      * @throws
      */
     function getAttribute($attr)

lib/pear/HTML/QuickForm/select.php

@@ -46,7 +46,7 @@ class HTML_QuickForm_select extends HTML_QuickForm_element {
     /**
      * Default values of the SELECT
      * 
-     * @var       string
+     * @var       array
      * @since     1.0
      * @access    private
      */

lib/pear/readme_moodle.txt

@@ -34,6 +34,7 @@ MDL-71126 - Quiz: Manual grading page size preference can get stuck at 0
              - New positiveint regex rule to check if the value is a positive integer
 MDL-76102 / MDL-77081
             PHP 8.1 passing null to a non-nullable argument of a built-in function is deprecated
+MDL-77164 - PHPdocs corrections
 
 Pear
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