librados/TestCase: inheret cleanup_default_namespace

No need to duplicate this code.

Signed-off-by: Sage Weil <sage@redhat.com>
ceph_test_rados_api: fix cleanup of cache pool

We can't simply try to delete everything in there because some items may
be whiteouts.  Instead, flush+evict everything, then remove overlay, and
*then* delete what remains.

Fixes: #9055
Signed-off-by: Sage Weil <sage@redhat.com>
ceph_test_rados_api_tier: fix cache cleanup (ec too)

Signed-off-by: Sage Weil <sage@redhat.com>
Merge pull request #2236 from ceph/wip-9055

ceph_test_rados_api_tier: fix cache pool cleanup during test

Reviewed-by: Samuel Just <sam.just@inktank.com>