[XFS] stop using xfs_itobp in xfs_iread

The only caller of xfs_itobp that doesn't have i_blkno setup is now
the initial inode read.  It needs access to the whole xfs_imap so using
xfs_inotobp is not an option.  Instead opencode the buffer lookup in
xfs_iread and kill all the functionality for the initial map from
xfs_itobp.

(First sent on October 21st)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>

fs/xfs/xfs_inode.h

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 705083a8..ec8b539 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -157,7 +157,7 @@
 #define	XFS_IFEXTIREC	0x08	/* Indirection array of extent blocks */
 
 /*
- * Flags for xfs_inotobp, xfs_itobp(), xfs_imap() and xfs_dilocate().
+ * Flags for xfs_inotobp, xfs_imap() and xfs_dilocate().
  */
 #define XFS_IMAP_LOOKUP		0x1
 #define XFS_IMAP_BULKSTAT	0x2
@@ -550,7 +550,7 @@
 			    struct xfs_buf **, int *, uint);
 int		xfs_itobp(struct xfs_mount *, struct xfs_trans *,
 			  struct xfs_inode *, struct xfs_dinode **,
-			  struct xfs_buf **, xfs_daddr_t, uint, uint);
+			  struct xfs_buf **, uint);
 void		xfs_dinode_from_disk(struct xfs_icdinode *,
 				     struct xfs_dinode *);
 void		xfs_dinode_to_disk(struct xfs_dinode *,