tests: complete the renaming framework_failure -> framework_failure_

tests: complete the renaming framework_failure -> framework_failure_

These changes were mostly mechanical, made by running the
following command:

  git grep -lw framework_failure | grep -v ChangeLog \
    | xargs perl -pi -e 's/\b(framework_failure)\b/${1}_/'

and then editing init.cfg and `tests/cp/cp-a-selinux' by hand.

* tests/init.cfg (framework_failure): Remove, `framework_failure_'
from init.sh should be used instead in the tests.
Remove now-obsolete "FIXME" comment.
(is_local_dir_, require_strace_, require_membership_in_two_groups_,
require_sparse_support_, skip_if_mcstransd_is_running_,
mkfifo_or_skip_) Use `framework_failure_', not `framework_failure'.
* Many test scripts: Likewise.