There are frequent references to *z in get_page_from_freelist.

Add an explicit zone variable that can be used in all these places.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>