ksm: update comments and docs to reference folio->mapping

The KSM code already stores and checks the stable node key via
folio->mapping, but the comment in ksm_get_folio() and the reverse mapping
documentation in ksm.rst still refer to page->mapping.

This is a pure wording update to match the folio-based implementation.  No
functional change is intended.

Link: https://lore.kernel.org/20260805105927.41987-1-hongfu.li@linux.dev
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Xu Xin <xu.xin16@zte.com.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Cc: Alex Shi <alexs@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yanteng Si <si.yanteng@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions