The jump labels are ambiguous and unclear and some of the error
paths are used inconsistently. Rules for error jumps are:

- use out_trans_cancel for unmodified transaction context
- use out_bmap_cancel on ENOSPC errors
- use out_trans_abort when transaction is likely to be dirty.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>