Convert s390 page handling macros to functions.  In particular this fixes a
problem with s390's SetPageUptodate macro which uses its input parameter
twice which again can cause subtle bugs.

[akpm@osdl.org: build fix]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>