mm/damon: update damos kerneldoc for stat field

mm/damon: update damos kerneldoc for stat field

Commit 0e92c2ee9f45 ("mm/damon/schemes: account scheme actions that
successfully applied") has replaced ->stat_count and ->stat_sz of 'struct
damos' with ->stat.  The commit mistakenly did not update the related
kernel doc comment, though.  Update the comment.

Link: https://lkml.kernel.org/r/20251216080128.42991-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>