xfs: remove redundant geometry information from xfs_da_state

It's carried in state->args->geo, so there's no need to duplicate it
and use more stack space than necessary.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>