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outdated comments.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/cifs/file.c b/fs/cifs/file.c
index 5ce540d..c03d074 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1902,7 +1902,7 @@
 	 * find_get_pages_tag seems to return a max of 256 on each
 	 * iteration, so we must call it several times in order to
 	 * fill the array or the wsize is effectively limited to
-	 * 256 * PAGE_CACHE_SIZE.
+	 * 256 * PAGE_SIZE.
 	 */
 	*found_pages = 0;
 	pages = wdata->pages;