xfstests: lock issues (089, 478, 484, 504)

These maybe independent problems; especially 089: (Note I'm running with -o flock)

089: can't lock lock file t_mtab~: Operation not supported can't lock lock file t_mtab~: Operation not supported completed 50 iterations

then takes a very very long time - not obvious why.

478 moans a lot about sem resource unavailable and then has:

• output mismatch (see /root/xfstests-dev/results//generic/478.out.bad) --- tests/generic/478.out 2019-10-14 14:59:46.000000000 -0400 +++ /root/xfstests-dev/results//generic/478.out.bad 2019-11-05 13:48:08.939177340 -0500 @@ -1,91 +1,181 @@ QA output created by 478 -get wrlck -lock could be placed -get wrlck -get wrlck -lock could be placed -get wrlck ... (Run 'diff -u /root/xfstests-dev/tests/generic/478.out /root/xfstests-dev/results//generic/478.out.bad' to see the entire diff)

484: +record lock is not preserved across execve(2)

504: +lock info not found