Fix missing function error.

bibcite_footnotes.module

@@ -69,7 +69,7 @@ function bibcite_footnotes_preprocess_footnote_list(&$variables) {
       ],
     ];
     $build = [];
-    $reference_entity_id = _bibcite_footnotes_get_reference_entity_id_from_bibcite_footnote($fn['reference']);
+    $reference_entity_id = $fn['reference'];
 
     $footnote_link_text = ($dont_show_backlink_text && $reference_entity_id) ? '^' : $fn['value'];
     if (!is_array($fn['ref_id'])) {