Add some needles for universal tests with btrfs default
    
    The 'universal' tests have quite a few failures if you run them
    on an image where btrfs is the default (currently they usually
    run on the Server DVD, where xfs-on-LVM is still the default).
    This fixes some of them, the others would need code fixes.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>