slub: make ->align unsigned int

Kmem cache alignment can't be negative.

Link: http://lkml.kernel.org/r/20180305200730.15812-13-adobriyan@gmail.com
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
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>

include/linux/slub_def.h

@@ -99,7 +99,7 @@ struct kmem_cache {
 	int refcount;		/* Refcount for slab cache destroy */
 	void (*ctor)(void *);
 	int inuse;		/* Offset to metadata */
-	int align;		/* Alignment */
+	unsigned int align;		/* Alignment */
 	unsigned int reserved;		/* Reserved bytes at the end of slabs */
 	unsigned int red_left_pad;	/* Left redzone padding size */
 	const char *name;	/* Name (only for display!) */

mm/slub.c

@@ -4896,7 +4896,7 @@ SLAB_ATTR_RO(slab_size);
 
 static ssize_t align_show(struct kmem_cache *s, char *buf)
 {
-	return sprintf(buf, "%d\n", s->align);
+	return sprintf(buf, "%u\n", s->align);
 }
 SLAB_ATTR_RO(align);