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.

tests/du/basic

@@ -19,12 +19,12 @@
 . "${srcdir=.}/init.sh"; path_prepend_ ../src
 print_ver_ du
 
-mkdir -p a/b d d/sub || framework_failure
+mkdir -p a/b d d/sub || framework_failure_
 
 # Ensure that these files contain more than 64 bytes, so that we don't
 # immediately disqualify file systems (e.g., NetApp) on which smaller
 # files take up zero disk blocks.
-printf '%*s' 257 make-sure-the-file-is-non-empty > a/b/F || framework_failure
+printf '%*s' 257 make-sure-the-file-is-non-empty > a/b/F || framework_failure_
 printf %4096s x > d/1
 cp d/1 d/sub/2