LU-7586 test: wait for remove in sanity-hsm test_406()

LU-7586 test: wait for remove in sanity-hsm test_406()

In sanity-hsm test_406() wait for the remove to complete before
continuing and call 'lfs mv' with the parent directory instead of the
individual file.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Idc22747c3e9da35ca40671735f18889345af5d9d
Reviewed-on: http://review.whamcloud.com/17828
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>