LU-14997 tests: Register "stack_trap" for sanity/104c

LU-14997 tests: Register "stack_trap" for sanity/104c

This patch is a minor improvement for calling cleanup
through 'stack_trap' versus doing right at the end of
the script.

Fixes: 8ee6e1c8825c ("LU-14565 ofd: Do not rely on tgd_blockbit")
Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: Iae2ca81091e0119f2117f4cd57b5cc2f6ac38c6c
Reviewed-on: https://review.whamcloud.com/44882
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Nunez <jnunez@whamcloud.com>