Change Bottlenecks volume mapping

Change Bottlenecks volume mapping

If mapping to host's /tmp, it won't clean all .log and .out files before
run a new test. It causes the results file including all previous results.
See https://build.opnfv.org/ci/view/dovetail/job/dovetail-apex-baremetal-default-mandatory-master/26/artifact/results/stress_logs/bottlenecks.stress.ping.out/*view*/
It will affect the results check.

Mapping to DOVETAIL_HOME/results/bottlenecks, which will always be cleaned
before running another test.

Change-Id: I22bfc871d6f041ae38308bf8e8f685993a376973
Signed-off-by: xudan <xudan16@huawei.com>