xfs: create a shared header file for format-related information

All of the buffer operations structures are needed to be exported
for xfs_db, so move them all to a common location rather than
spreading them all over the place. They are verifying the on-disk
format, so while xfs_format.h might be a good place, it is not part
of the on disk format.

Hence we need to create a new header file that we centralise these
related definitions. Start by moving the bffer operations
structures, and then also move all the other definitions that have
crept into xfs_log_format.h and xfs_format.h as there was no other
shared header file to put them in.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_attr_leaf.h

@@ -336,6 +336,4 @@ void	xfs_attr3_leaf_hdr_from_disk(struct xfs_attr3_icleaf_hdr *to,
 void	xfs_attr3_leaf_hdr_to_disk(struct xfs_attr_leafblock *to,
 				   struct xfs_attr3_icleaf_hdr *from);
 
-extern const struct xfs_buf_ops xfs_attr3_leaf_buf_ops;
-
 #endif	/* __XFS_ATTR_LEAF_H__ */