mm/memcontrol: remove unused for_each_mem_cgroup macro and cleanup

Commit 7e1c0d6f58207 ("memcg: switch lruvec stats to rstat") removed the
last caller of for_each_mem_cgroup back in 2021, and there have not been
any new callers since.  Remove the macro.

A comment in mem_cgroup_css_online has also been out of date since 2021,
when 2bfd36374edd9 ("mm: vmscan: consolidate shrinker_maps handling code")
open-coded the for_each_mem_cgroup iterator.  Update the comment.

Finally, 99430ab8b804c ("mm: introduce BPF kfuncs to access memcg
statistics and events") added a second declaration for memcg_events to
include/linux/memcontrol.h, duplicating the one in mm/memcontrol-v1.h. 
Let's clean that up too.

No functional changes intended.

Link: https://lore.kernel.org/20260624183700.1152742-1-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: SeongJae Park <sj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions