xfs: remove unused fields from struct xbtree_ifakeroot

Remove these unused fields since nobody uses them.  They should have
been removed years ago in a different cleanup series from Christoph
Hellwig.

Fixes: daf83964 ("xfs: move the per-fork nextents fields into struct xfs_ifork")
Fixes: f7e67b20 ("xfs: move the fork format fields into struct xfs_ifork")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/libxfs/xfs_btree_staging.h

@@ -37,12 +37,6 @@ struct xbtree_ifakeroot {
 
 	/* Number of bytes available for this fork in the inode. */
 	unsigned int		if_fork_size;
-
-	/* Fork format. */
-	unsigned int		if_format;
-
-	/* Number of records. */
-	unsigned int		if_extents;
 };
 
 /* Cursor interactions with fake roots for inode-rooted btrees. */