SLQB: fix slab MAX_ORDER calculation

SLQB didn't consider MAX_ORDER when defining which sizes of kmalloc
slabs to create. It panics at boot if it tries to create a cache
which exceeds MAX_ORDER-1.

The patch fixes PowerPC boot failures discussed here:

  http://lkml.org/lkml/2009/4/28/198Reported-by: Sachin Sant <sachinp@in.ibm.com>
Tested-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

include/linux/slqb_def.h

@@ -172,7 +172,8 @@ struct kmem_cache {
 #endif
 
 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
-#define KMALLOC_SHIFT_SLQB_HIGH (PAGE_SHIFT + 9)
+#define KMALLOC_SHIFT_SLQB_HIGH (PAGE_SHIFT + 			\
+				 ((9 <= (MAX_ORDER - 1)) ? 9 : (MAX_ORDER - 1)))
 
 extern struct kmem_cache kmalloc_caches[KMALLOC_SHIFT_SLQB_HIGH + 1];
 extern struct kmem_cache kmalloc_caches_dma[KMALLOC_SHIFT_SLQB_HIGH + 1];