Fixed bteam issue #37235: 5.0 trees now will work correctly in pb2 and

will not display "indicated result file not found" due to wrongly named
var directory.

mysql-test/collections/default.push

-perl mysql-test-run.pl --timer --force --vardir=n_stm --comment=n_stm
-perl mysql-test-run.pl --timer --force --vardir=ps_stm --comment=ps_stm --ps-protocol
+perl mysql-test-run.pl --timer --force --vardir=var-n_stm --comment=n_stm
+perl mysql-test-run.pl --timer --force --vardir=var-ps_stm --comment=ps_stm --ps-protocol