slab, slub, slob: convert slab_flags_t to 32-bit

struct kmem_cache::flags is "unsigned long" which is unnecessary on
64-bit as no flags are defined in the higher bits.

Switch the field to 32-bit and save some space on x86_64 until such
flags appear:

	add/remove: 0/0 grow/shrink: 0/107 up/down: 0/-657 (-657)
	function                                     old     new   delta
	sysfs_slab_add                               720     719      -1
				...
	check_object                                 699     676     -23

[akpm@linux-foundation.org: fix printk warning]
Link: http://lkml.kernel.org/r/20171021100635.GA8287@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/slub.c b/mm/slub.c
index 482d1da..33957fd 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -194,9 +194,9 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
 
 /* Internal SLUB flags */
 /* Poison object */
-#define __OBJECT_POISON		((slab_flags_t __force)0x80000000UL)
+#define __OBJECT_POISON		((slab_flags_t __force)0x80000000U)
 /* Use cmpxchg_double */
-#define __CMPXCHG_DOUBLE	((slab_flags_t __force)0x40000000UL)
+#define __CMPXCHG_DOUBLE	((slab_flags_t __force)0x40000000U)
 
 /*
  * Tracking user of a slab.
@@ -3657,7 +3657,7 @@ static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags)
 	if (flags & SLAB_PANIC)
 		panic("Cannot create slab %s size=%lu realsize=%u order=%u offset=%u flags=%lx\n",
 		      s->name, (unsigned long)s->size, s->size,
-		      oo_order(s->oo), s->offset, flags);
+		      oo_order(s->oo), s->offset, (unsigned long)flags);
 	return -EINVAL;
 }