qa: fixup cephtool test when MDS exists

qa: fixup cephtool test when MDS exists

We added MDS resetting code here a while back,
but the order of operations was such that a
"cluster up" was being run between a fail_all_mds
and the point at which we needed the map not to
be interfered with (testing setmap).

Also the new fs create/destroy cycles for testing
EC pool handling were missing calls to stop the
daemons before fs rm.

Signed-off-by: John Spray <john.spray@redhat.com>