Fix floating bug with osprofiler test
Fix floating bug with osprofiler test

The failures of `test_profiler_init` test was quite high. The issue of
it relates to wrong mocking.

Change-Id: Id1bc1bd045c9b3340b474c54bc8945cb1d6937fa

yeming233/rally,openstack/rally,openstack/rally,openstack/rally,openstack/rally,yeming233/rally