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outdated comments.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/Documentation/filesystems/cramfs.txt b/Documentation/filesystems/cramfs.txt
index 31f53f0..4006298 100644
--- a/Documentation/filesystems/cramfs.txt
+++ b/Documentation/filesystems/cramfs.txt
@@ -38,7 +38,7 @@
 which the timestamp reverts to 1970, i.e. moves backwards in time.
 
 Currently, cramfs must be written and read with architectures of the
-same endianness, and can be read only by kernels with PAGE_CACHE_SIZE
+same endianness, and can be read only by kernels with PAGE_SIZE
 == 4096.  At least the latter of these is a bug, but it hasn't been
 decided what the best fix is.  For the moment if you have larger pages
 you can just change the #define in mkcramfs.c, so long as you don't