LU-16455 tests: recovery-small test_139() fix

LU-16455 tests: recovery-small test_139() fix

mds device calculated before stop () can not be used
after stop() because of a device-mapper device is removed and
facet device is restored:
  stop () ->
    elif dm_flakey_supported $facet; then
      if [[ -n ${!failover_host} &&
               ${!failover_host} != ${!host} ]]
         dm_cleanup_dev $facet ->
               unexport_dm_dev $facet

Without this fix test_139 fails on failover setup:
  losetup: /dev/mapper/mds1_flakey: failed to set up loop device:
    No such file or directory

To reproduce the failure just run:
  sh llmountcleanup.sh
  ONLY=139 sh recovery-small.sh
on failover setup where mds1_HOST != mds1failover_HOST

Fixes: 4597fa7d88 ("LU-13061 osp: check catlog FID after reading in")
Test-Parameters: trivial testlist="recovery-small" failover=true iscsi=1 \
  env=ONLY=139,SLOW=yes mdssizegb=10 clientcount=4 osscount=2 mdscount=2 \
  mdtcount=2 austeroptions=-R
Test-Parameters: trivial testlist="recovery-small" failover=true iscsi=1 \
  env=FAILURE_MODE=HARD,ONLY=139,SLOW=yes mdssizegb=10 clientcount=4 \
  osscount=2 mdscount=2 mdtcount=2 austeroptions=-R
Signed-off-by: Elena Gryaznova <elena.gryaznova@hpe.com>
Reviewed-by: Vladimir Saveliev <vlaidimir.saveliev@hpe.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
HPE-bug-id: LUS-10912
Change-Id: I67d98f633de4023a4430b55c6b4d308c7f17d988
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49579
Tested-by: Maloo <maloo@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Vladimir Saveliev <vladimir.saveliev@hpe.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>