Coding Standards: Fix the Squiz.PHP.DisallowMultipleAssignments violations in wp-admin.

See #47632.


Built from https://develop.svn.wordpress.org/trunk@45583


git-svn-id: http://core.svn.wordpress.org/trunk@45394 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/import.php

@@ -101,7 +101,8 @@ if ( empty( $importers ) ) {
 
 	<?php
 	foreach ( $importers as $importer_id => $data ) {
-		$plugin_slug         = $action = '';
+		$plugin_slug         = '';
+		$action              = '';
 		$is_plugin_installed = false;
 
 		if ( isset( $data['install'] ) ) {