[XFS] kill struct xfs_btree_hdr

This type is only embedded in struct xfs_btree_block and never used
directly. By moving the fields directly into struct xfs_btree_block a lot
of the macros for struct xfs_btree_sblock and struct xfs_btree_lblock can
be used for struct xfs_btree_block too now which helps greatly with some
of the migrations during implementing the generic btree code.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32174a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_btree.h b/fs/xfs/xfs_btree.h
index 1f528a2..332b9f1 100644
--- a/fs/xfs/xfs_btree.h
+++ b/fs/xfs/xfs_btree.h
@@ -63,15 +63,10 @@
 /*
  * Combined header and structure, used by common code.
  */
-typedef struct xfs_btree_hdr
-{
+typedef struct xfs_btree_block {
 	__be32		bb_magic;	/* magic number for block type */
 	__be16		bb_level;	/* 0 is a leaf */
 	__be16		bb_numrecs;	/* current # of data records */
-} xfs_btree_hdr_t;
-
-typedef struct xfs_btree_block {
-	xfs_btree_hdr_t	bb_h;		/* header */
 	union {
 		struct {
 			__be32		bb_leftsib;