xfs: stop using q_core.d_id in the quota code

Add a dquot id field to the incore dquot, and use that instead of the
one in qcore.  This eliminates a bunch of endian conversions and will
eventually allow us to remove qcore entirely.

We also rearrange the start of xfs_dquot to remove padding holes, saving
8 bytes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c
index fc21e48..8c1fdf3 100644
--- a/fs/xfs/xfs_dquot_item.c
+++ b/fs/xfs/xfs_dquot_item.c
@@ -53,7 +53,7 @@ xfs_qm_dquot_logitem_format(
 	qlf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_QFORMAT);
 	qlf->qlf_type = XFS_LI_DQUOT;
 	qlf->qlf_size = 2;
-	qlf->qlf_id = be32_to_cpu(qlip->qli_dquot->q_core.d_id);
+	qlf->qlf_id = qlip->qli_dquot->q_id;
 	qlf->qlf_blkno = qlip->qli_dquot->q_blkno;
 	qlf->qlf_len = 1;
 	qlf->qlf_boffset = qlip->qli_dquot->q_bufoffset;