Mysql create trigger if not exist
There is no CREATE TRIGGER IF NOT EXISTS

There is DROP TRIGGER IF EXISTS

You must execute the trigger's creation as follows:

USE xxx_admin
DELIMITER $$
DROP TRIGGER IF EXISTS test_AFTER_UPDATE $$
CREATE DEFINER=`root`@`localhost` TRIGGER `xxx_admin`.`test_AFTER_UPDATE`
AFTER UPDATE ON `test` FOR EACH ROW
BEGIN
    INSERT INTO auditTest 
    select *, now() from test where id = NEW.id;
END $$
DELIMITER ;


GIVE IT A TRY !!!

As for you error, using IF like that is not valid from the CLI.