Rename memcg_check_events() into memcg1_check_events() for consistency
with other cgroup v1-specific functions.

Link: https://lkml.kernel.org/r/20240625005906.106920-8-roman.gushchin@linux.devSigned-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>