LU-17392 build: compatibility updates for kernel 6.7

LU-17392 build: compatibility updates for kernel 6.7

Linux commit v6.6-rc4-53-gc42d50aefd17
  mm: shrinker: add infrastructure for dynamically allocating
      shrinker

Users of struct shrinker must dynamically allocate shrinker objects
to avoid run-time warnings.

Provide a wrapper for older kernels to alloc+register shinkers
and unregister+free.

Use get_group_info() and put_group_info() wrappers instead of
open coding the reference counting on group_info.usage

Lustre-change: https://review.whamcloud.com/53621
Lustre-commit: TBD (from 7e8165620e1943189d63ce4770c7722fa309a58e)

Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: Ie07bdb7fe3eb6060bd84f95f860f1b53d120a605
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54323
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>