fix typos
Signed-off-by: wangxinyu <wangxinyu@inspur.com>
Rank 0 is part of the failed set and is pending to be taken over by a standby
MDS. If this state persists, it indicates no suitable MDS daemons found to be
assigned to this rank. This may be caused by not enough standby daemons, or all
-standby daemons have incompatible campat (see also :ref:`upgrade-mds-cluster`).
+standby daemons have incompatible compat (see also :ref:`upgrade-mds-cluster`).
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