xfstests: remove test expunge file support

xfstests: remove test expunge file support

Check supports an expunge file for tests - a way of marking tests
not to run even if you specify it to run. Use is like this:

$ echo 002 > expunged
test-2:~/src/xfstests-dev$ sudo ./check 001-003
FSTYP         -- xfs (debug)
PLATFORM      -- Linux/x86_64 test-2 3.5.0-rc1-dgc+
MKFS_OPTIONS  -- -f -bsize=4096 /dev/vdb
MOUNT_OPTIONS -- /dev/vdb /mnt/scratch

001 4s ... 4s
002 - expunged
003 0s ... 0s
Ran: 001 002 003
Not run:1
Passed all 2 tests

This is arguably useful(*), but gets in the way of splitting up the
tests into multiple directories. Remove it for now, but such
functionality should be considered for re-implementation at a later
date.

(*) e.g. having a different "expunged" file for each distro release
you have to test to avoid the tests known to fail due to fixes or
features that will never be back ported to older releases....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>