sys_vars.wait_timeout_func failed in buildbot with wrong result

sys_vars.wait_timeout_func               w3 [ fail ]

        Test ended at 2017-05-08 12:47:49

CURRENT_TEST: sys_vars.wait_timeout_func

--- /usr/local/mariadb-10.1.24-linux-i686/mysql-test/suite/sys_vars/r/wait_timeout_func.result	2017-05-08 11:15:54.000000000 +0200

+++ /usr/local/mariadb-10.1.24-linux-i686/mysql-test/suite/sys_vars/r/wait_timeout_func.reject	2017-05-08 12:47:49.000000000 +0200

@@ -28,5 +28,5 @@

 SELECT info FROM information_schema.processlist

 SELECT UNIX_TIMESTAMP() - @start_time >= <global_value> + <session_value>;;

 UNIX_TIMESTAMP() - @start_time >= <global_value> + <session_value>;

-1

+0

 SET @@global.wait_timeout= @start_value;

mysqltest: Result content mismatch