di_format value and can be one of 2 formats:
XFS_DINODE_FMT_LOCAL: The symbolic link is fully contained within the inode. This is accessed by casting the return value from XFS_DFORK_DPTR to char*.
XFS_DINODE_FMT_EXTENTS: The actual symlink is located in another filesystem block, the inode contains the extents to these filesystem blocks (xfs_bmbt_rec_t*).