Request for cherry-picking commit 4a625ce from Linus' tree

[Vaibhav Rustagi <vaibhavrustagi@xxxxxxxxxx>]

Hello,

In order to resolve CVE-2023-23005 in kernel v6.1 stable tree, I would
like to request cherry-picking the below commit:

mm/demotion: fix NULL vs IS_ERR checking in memory_tier_init (4a625ce)

The above commit is needed only in v6.1 stable kernel tree since older
LTS versions don't have the implementation which introduced the
problem.

Thanks,
Vaibhav