Revert "ceph: allow rename operation under different quota realms"

This reverts commit dffdcd71.

When doing a rename across quota realms, there's a corner case that isn't
handled correctly.  Here's a testcase:

  mkdir files limit
  truncate files/file -s 10G
  setfattr limit -n ceph.quota.max_bytes -v 1000000
  mv files limit/

The above will succeed because ftruncate(2) won't immediately notify the
MDSs with the new file size, and thus the quota realms stats won't be
updated.

Since the possible fixes for this issue would have a huge performance impact,
the solution for now is to simply revert to returning -EXDEV when doing a cross
quota realms rename.

URL: https://tracker.ceph.com/issues/48203


Signed-off-by: Luis Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>