LU-5047 tests: correct cleanup files in sanity.sh

LU-5047 tests: correct cleanup files in sanity.sh

Don't remove all files from Lustre share. Create files that will be
cleaned up at the end tests session in check_and_cleanup_lustre().

Fix cleanup for test_54c.

Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Change-Id: I23624b9d14e7de3423b82b4a5b8508c4820c55d4
Reviewed-on: http://review.whamcloud.com/10291
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>