Narrow device_type needle area to fix match
    
    In the most recent Rawhide compose, anaconda has changed how it
    names volume groups (again), and now the VGs in openQA installs
    have rather longer names. This winds up causing a problem for
    this needle: the column where the 'Device Type' dropdown is
    placed actually gets narrower (because the column to the right,
    which has the volume group name in it, is wider), and so the
    dropdown box is narrower, and the arrow protrudes into the area
    which the needle expects not to have an arrow in it. So, let's
    make the match area slightly narrower.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>