Docs: In various @return tags, list the expected type first, instead of WP_Error.

See #48303.

git-svn-id: https://develop.svn.wordpress.org/trunk@46696 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-plugin-upgrader.php

@@ -450,7 +450,7 @@ class Plugin_Upgrader extends WP_Upgrader {
 	 * @param string        $local_destination
 	 * @param string        $remote_destination
 	 * @param array         $plugin
-	 * @return WP_Error|bool
+	 * @return bool|WP_Error
 	 */
 	public function delete_old_plugin( $removed, $local_destination, $remote_destination, $plugin ) {
 		global $wp_filesystem;