xfs: Remove unused xfs_attr_*_args

xfs: Remove unused xfs_attr_*_args

Source kernel commit: 73159fc27c6944ebe55e6652d6a1981d7cb3eb4a

Remove xfs_attr_set_args, xfs_attr_remove_args, and xfs_attr_trans_roll.
These high level loops are now driven by the delayed operations code,
and can be removed.

Additionally collapse in the leaf_bp parameter of xfs_attr_set_iter
since we only have one caller that passes dac->leaf_bp

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>