xfs: clean up long conditionals in xfs_iwalk_ichunk_ra

	agbno = XFS_AGINO_TO_AGBNO(mp, irec->ir_startino);

	blk_start_plug(&plug);

	for (i = 0;

	     i < XFS_INODES_PER_CHUNK;

	     i += igeo->inodes_per_cluster,

			agbno += igeo->blocks_per_cluster) {

		if (xfs_inobt_maskn(i, igeo->inodes_per_cluster) &

		    ~irec->ir_free) {

	for (i = 0; i < XFS_INODES_PER_CHUNK; i += igeo->inodes_per_cluster) {

		xfs_inofree_t	imask;

		imask = xfs_inobt_maskn(i, igeo->inodes_per_cluster);

		if (imask & ~irec->ir_free) {

			xfs_btree_reada_bufs(mp, agno, agbno,

					igeo->blocks_per_cluster,

					&xfs_inode_buf_ops);

		}

		agbno += igeo->blocks_per_cluster;

	}

	blk_finish_plug(&plug);

}