Revert "Add userspace notification for MGLRU generation creation"

This reverts commit 02e000eb.

Reason for revert: Causing health.DiagnosticsRun.cpu_stress to fail
See https://buganizer.corp.google.com/issues/261753137#comment9
https://b.corp.google.com/issues/260967742

 seems to be the cause, so the same problem can happen in the arcvm kernel, too.

Original change's description:
> Add userspace notification for MGLRU generation creation
>
> Add sysfs_notify in inc_max_seq function so that every time a new MGLRU
> generation is created so that user space programs can notice that by
> polling /sys/kernel/mm/lru_gen/admin.
>
> BUG=b:245255700
> TEST=Follow these steps:
> - Open /sys/kernel/mm/lru_gen/admin and read it once.
> - poll the fd you opend and wait for the POLLPRI event.
> - Put some memory pressure on the kernel and see if the poll ever
>   returns.
>
> Signed-off-by: Koki Ryu <kokiryu@google.com>
>
> Change-Id: I11023f002ecf235a9933bb87fbd3183e9b08a9ca
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/3936130


> Commit-Queue: Kameron Lutes <kalutes@chromium.org>
> Tested-by: Koki Ryu <kokiryu@chromium.org>
> Reviewed-by: Charles William Dick <cwd@google.com>
> Reviewed-by: Kameron Lutes <kalutes@chromium.org>

Bug: b:245255700
Change-Id: I40313bea25e026b022da69eb5e2a8bbd6ca838bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4100085


Auto-Submit: Koki Ryu <kokiryu@chromium.org>
Commit-Queue: Suleiman Souhlal <suleiman@chromium.org>
Reviewed-by: Suleiman Souhlal <suleiman@chromium.org>
Tested-by: Koki Ryu <kokiryu@chromium.org>
Signed-off-by: Richard Fung <richardfung@google.com>