xfs: merge xfs_dir2_data_freescan and xfs_dir2_data_freescan_int

There is no real need for xfs_dir2_data_freescan wrapper, so rename
xfs_dir2_data_freescan_int to xfs_dir2_data_freescan and let the
callers dereference the mount pointer from the inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>