libgfs2, fsck.gfs2: simplify block_query code
    
    This patch simplifies the block query code.  Now that the blockmap
    code doesn't have the duplicate block reference responsibilities,
    we don't need the query info to be in its own structure.  The
    block query can be reduced to a simple fetch from memory and mask
    off the bits we need.  The block query used to check for a valid
    block range.  Now, for performance reasons, that's the
    responsibility of the caller.  Most of the callers check for a
    valid range anyway, so checking it in the query was a waste of
    time.  This is for better performance and makes the code simpler
    and more readable.
    
    rhbz#455300