Fixes for 5.14-rc:
 * Fix shrink eligibility checking when sparse inode clusters enabled.
 * Reset '..' directory entries when unlinking directories to prevent
   verifier errors if fs is shrinked later.
 * Don't report unusable extent size hints to FSGETXATTR.
 * Don't warn when extent size hints are unusable because the sysadmin
   configured them that way.
 * Fix insufficient parameter validation in GROWFSRT ioctl.
 * Fix integer overflow when adding rt volumes to filesystem.