xfs_io: allow foreign FSes to show FS_IOC_FSGETXATTR details

xfs_io: allow foreign FSes to show FS_IOC_FSGETXATTR details

Currently with stat we only show FS_IOC_FSGETXATTR details if the
filesystem is XFS. With extsize support also coming to ext4 and possibly
other filesystems, make sure to allow foreign FSes to display these details
when "stat" or "statx" is used.

(Thanks to Dave for suggesting implementation of print_extended_info())

Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>