xfs: move ftype conversion functions to libxfs

These functions are needed in userspace for repair and mkfs to
do the right thing. Move them to libxfs so they can be easily
shared.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index ec6dcdc..4b7802a 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -37,7 +37,7 @@
 #include "xfs_icache.h"
 #include "xfs_symlink.h"
 #include "xfs_da_btree.h"
-#include "xfs_dir2_priv.h"
+#include "xfs_dir2.h"
 #include "xfs_dinode.h"
 #include "xfs_trans_space.h"