mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage

Mostly direct substitution with occasional adjustment or removing
outdated comments.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 2dae608..91117ad 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -573,7 +573,7 @@
  * only partially being written to.
  *
  * If @nr_pages is greater than one, we are guaranteed that the cluster size is
- * greater than PAGE_CACHE_SIZE, that all pages in @pages are entirely inside
+ * greater than PAGE_SIZE, that all pages in @pages are entirely inside
  * the same cluster and that they are the entirety of that cluster, and that
  * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
  *