qa/common.qt: make _cleanup_qt() match default _cleanup() for tmp file cleanup
qa/common.qt: make _cleanup_qt() match default _cleanup() for tmp file cleanup

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp