Test that we properly ignore old growfs-induced junk in the unused
portion of secondary V4 superblocks; at one point this would
trip up the verifiers, and cause a subsequent growfs to fail.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>