Removed unnecessary function

We were supporting older versions of Moodle so
it was necessary if we only wanted one branch.

element/image/lib.php

@@ -161,7 +161,7 @@ class customcert_element_image extends customcert_element_base {
             }
         }
 
-        customcert_perform_asort($arrfiles);
+        core_collator::asort($arrfiles);
         $arrfiles = array_merge(array('0' => get_string('noimage', 'customcert')), $arrfiles);
 
         return $arrfiles;

element/userfield/lib.php

@@ -61,7 +61,7 @@ class customcert_element_userfield extends customcert_element_base {
         }
         // Combine the two.
         $fields = $userfields + $customfields;
-        customcert_perform_asort($fields);
+        core_collator::asort($fields);
 
         // Create the select box where the user field is selected.
         $mform->addElement('select', 'userfield', get_string('userfield', 'customcertelement_userfield'), $fields);

locallib.php

@@ -119,7 +119,7 @@ function customcert_get_elements() {
         }
     }
 
-    customcert_perform_asort($options);
+    core_collator::asort($options);
     return $options;
 }
 
@@ -713,16 +713,3 @@ function customcert_generate_report_file($customcert, $users, $type) {
     // Close the workbook.
     $workbook->close();
 }
-
-/**
- * Perform asort on a given array.
- *
- * @param array $fields
- */
-function customcert_perform_asort(&$fields) {
-    if (class_exists('core_collator')) {
-        core_collator::asort($fields);
-    } else {
-        collatorlib::asort($fields);
-    }
-}