mm: list_lru: remove unused macro list_lru_init_key()

list_lru_init_key() isn't used by anyone, remove it to clean up.

Link: https://lkml.kernel.org/r/20231228062715.338672-2-haifeng.xu@shopee.com


Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>