gfs2_edit savemeta doesn't save all leaf blocks for large dirs
    
    This patch changes the gfs2_edit "savemeta" option so that it
    processes exhash directories the same way that fsck.gfs2 does,
    namely, it does a read of the hash table and saves all the
    leaf blocks from that.  Before it was trying to traverse the
    blocks, but that only works for medium-size exhash directories.
    
    rhbz#679565