[XFS] Make the bulkstat_one compat ioctl handling more sane

Currently the compat formatter was handled by passing
in "private_data" for the xfs_bulkstat_one formatter,
which was really just another formatter... IMHO this
got confusing.

Instead, just make a new xfs_bulkstat_one_compat
formatter for xfs_bulkstat, and call it via a wrapper.

Also, don't translate the ioctl nrs into their native
counterparts, that just clouds the issue; we're in a
compat handler anyway, just switch on the 32-bit cmds.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

fs/xfs/xfs_itable.h

@@ -73,6 +73,18 @@ typedef int (*bulkstat_one_fmt_pf)(  /* used size in bytes or negative error */
 	void			__user *ubuffer, /* buffer to write to */
 	const xfs_bstat_t	*buffer);        /* buffer to read from */
 
+int
+xfs_bulkstat_one_int(
+	xfs_mount_t		*mp,
+	xfs_ino_t		ino,
+	void			__user *buffer,
+	int			ubsize,
+	bulkstat_one_fmt_pf	formatter,
+	xfs_daddr_t		bno,
+	int			*ubused,
+	void			*dibuff,
+	int			*stat);
+
 int
 xfs_bulkstat_one(
 	xfs_mount_t		*mp,