xfs: Remove the macro XFS_BUF_PTR

Remove the definition and usages of the macro XFS_BUF_PTR.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index 46e54ad..9a0aa76 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -1240,7 +1240,7 @@
 	do_div(j, sizeof(xfs_dqblk_t));
 	ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
 #endif
-	ddq = (xfs_disk_dquot_t *)XFS_BUF_PTR(bp);
+	ddq = bp->b_addr;
 	for (j = 0; j < mp->m_quotainfo->qi_dqperchunk; j++) {
 		/*
 		 * Do a sanity check, and if needed, repair the dqblk. Don't