LU-10211 tests: conf_sanity test 102 don't call lustre_rmmod

LU-10211 tests: conf_sanity test 102 don't call lustre_rmmod

When testing from build tree lustre/scripts is not in the
PATH, so need to call $LUSTRE_RMMOD that knows the actual
path to that script.

Change-Id: I7e8fa2b4ac8c2d03d1a9a6865c50dbae6c139a30
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: https://review.whamcloud.com/30001
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>