slub: change kmem_cache->align to record the real alignment

kmem_cache->align records the original align parameter value specified
by users. Function calculate_alignment might change it based on cache
line size. So change kmem_cache->align correspondingly.
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

mm/slub.c

@@ -2422,6 +2422,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
 	 * on bootup.
 	 */
 	align = calculate_alignment(flags, align, s->objsize);
+	s->align = align;
 
 	/*
 	 * SLUB stores one object immediately after another beginning from