qa: cp run_xfstests.sh run_xfstests-obsolete.sh

run_xfstests.sh is going to be updated in the next commit to be able to
drive newer xfstests.  Among other things, the new xfstests proper
doesn't support listing tests in ranges, which is what the qemu wrapper
(run_xfstests_qemu.sh) relies on.  So keep a copy of the old
run_xfstests.sh around until the qemu vm image is regenerated and the
up-to-date exclusion list for that kernel is shaken out.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
qa: catch up with xfstests changes

Back in 2013 xfstests were rearranged, which also changed the way
./check parses test lists.  Catch up with those changes.  Note that
tests can no longer be listed in ranges, we only accept individual
tests and test groups (e.g. -g quick).

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
qa: add run_xfstests_krbd.sh wrapper

As run_xfstests.sh does no longer accept test lists, wrap it to provide
an expunge file with a list of tests we want to skip for krbd runs.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>