placeholder: whitelist MDS_ALL_DOWN, MDS_UP_LESS_THAN_MAX  by default
placeholder: whitelist MDS_ALL_DOWN, MDS_UP_LESS_THAN_MAX  by default

because, in ceph/qa/tasks/ceph.py, we start mon, mgr, osd, and then mds.
there is a time window where there is no mds around, but mgr is checking
mdsmap for MDS_ALL_DOWN errors. there is no way to disable this check in
this time window. so we just whitelist MDS_ALL_DOWN here.

Signed-off-by: Kefu Chai <a4b264ee037c625052534d60505bfd0db4776ac4@redhat.com>

SUSE/teuthology,dmick/teuthology,ceph/teuthology,SUSE/teuthology,ktdreyer/teuthology,ceph/teuthology,SUSE/teuthology,dmick/teuthology,ktdreyer/teuthology,dmick/teuthology