In the lshift/rshift functions we don't use the key variable for
anything now, so remove the variable and its initializer.  The
update_keys functions figure out the key for a block on their own.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>