mm/slub: use helper macro __ATTR_XX_MODE for SLAB_ATTR(_RO)

This allows more concise code, and VERIFY_OCTAL_PERMISSIONS() can help
validate any future change.

Signed-off-by: Lianjie Zhang <zhanglianjie@uniontech.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20220306073818.15089-1-zhanglianjie@uniontech.com
diff --git a/mm/slub.c b/mm/slub.c
index 2614740..d33aada 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5344,12 +5344,10 @@ struct slab_attribute {
 };
 
 #define SLAB_ATTR_RO(_name) \
-	static struct slab_attribute _name##_attr = \
-	__ATTR(_name, 0400, _name##_show, NULL)
+	static struct slab_attribute _name##_attr = __ATTR_RO_MODE(_name, 0400)
 
 #define SLAB_ATTR(_name) \
-	static struct slab_attribute _name##_attr =  \
-	__ATTR(_name, 0600, _name##_show, _name##_store)
+	static struct slab_attribute _name##_attr = __ATTR_RW_MODE(_name, 0600)
 
 static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
 {