tests: improve mds tests
tests: improve mds tests

the expected number of mds daemon consist of number of daemons that are
'up' + number of daemons 'up:standby'.

Signed-off-by: Guillaume Abrioux <30a9df5a0293a6108675377fa1673f7aa713f915@redhat.com>
(cherry picked from commit c94ada69e80d7a1ddfbd2de2b13086d57a6fdfcd)
Signed-off-by: Guillaume Abrioux <30a9df5a0293a6108675377fa1673f7aa713f915@redhat.com>

fgal/ceph-ansible,fgal/ceph-ansible