xfs: remove xfs_buf_t typedef

Prepare for kernel xfs_buf  alignment by getting rid of the
xfs_buf_t typedef from userspace.

[darrick: This patch is a port of a userspace patch removing the
xfs_buf_t typedef in preparation to make the userspace xfs_buf code
behave more like its kernel counterpart.]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 0356f2e..dc0be2a 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -412,7 +412,7 @@ xfs_buf_item_unpin(
 	int			remove)
 {
 	struct xfs_buf_log_item	*bip = BUF_ITEM(lip);
-	xfs_buf_t		*bp = bip->bli_buf;
+	struct xfs_buf		*bp = bip->bli_buf;
 	int			stale = bip->bli_flags & XFS_BLI_STALE;
 	int			freed;
 
@@ -942,7 +942,7 @@ xfs_buf_item_free(
  */
 void
 xfs_buf_item_relse(
-	xfs_buf_t	*bp)
+	struct xfs_buf	*bp)
 {
 	struct xfs_buf_log_item	*bip = bp->b_log_item;