LU-10226 tests: properly check for fileset clear and error

LU-10226 tests: properly check for fileset clear and error

Make sure fileset info on nodemap is cleared everywhere before
continuing test.
Also, properly exit on this error.

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I1d117ffef6c4a1002d3eba47a301e64830be4b4f
Reviewed-on: https://review.whamcloud.com/30037
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Emoly Liu <emoly.liu@intel.com>
Reviewed-by: Stephan Thiell <sthiell@stanford.edu>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>