[XFS] replace b_fspriv with b_mount

Replace the b_fspriv pointer and it's ugly accessors with a properly types
xfs_mount pointer.  Also switch log reocvery over to it instead of using
b_fspriv for the mount pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index cd89c56..b9c304a 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1085,7 +1085,7 @@
 	bp->b_flags &= ~(XBF_READ | XBF_DELWRI | XBF_READ_AHEAD);
 	bp->b_flags |= (XBF_WRITE | XBF_ASYNC | _XBF_RUN_QUEUES);
 
-	bp->b_fspriv3 = mp;
+	bp->b_mount = mp;
 	bp->b_strat = xfs_bdstrat_cb;
 	return xfs_bdstrat_cb(bp);
 }
@@ -1098,7 +1098,7 @@
 	XB_TRACE(bp, "bdwrite", 0);
 
 	bp->b_strat = xfs_bdstrat_cb;
-	bp->b_fspriv3 = mp;
+	bp->b_mount = mp;
 
 	bp->b_flags &= ~XBF_READ;
 	bp->b_flags |= (XBF_DELWRI | XBF_ASYNC);