btrfs/029: filter mkfs and cp output
I noticed while testing a different mkfs option that btrfs/029 was
failing because it was getting the extra output from our mkfs.btrfs.
After I fixed that I was still failing because my version of cp will
spit out the source and destination files, not just the destination
file. So redirect _scratch_mkfs to /dev/null like everybody does
and make the golden output just expect to see "cp failed" instead of
the cp specific output. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>