blk-mq: fix kabi broken in struct bio

hulk inclusion
category: bugfix
bugzilla: 187921, https://gitee.com/openeuler/kernel/issues/I66VDB
CVE: NA

--------------------------------

Enable CONFIG_BLK_CGROUP_IOCOST will cause kabi broken, use reserved
fields to fix it.
Signed-off-by: NLi Nan <linan122@huawei.com>
Reviewed-by: NHou Tao <houtao1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/linux/blk_types.h

@@ -234,9 +234,6 @@ struct bio {
 	 */
 	struct blkcg_gq		*bi_blkg;
 	struct bio_issue	bi_issue;
-#ifdef CONFIG_BLK_CGROUP_IOCOST
-	u64			bi_iocost_cost;
-#endif
 #endif
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
@@ -263,7 +260,11 @@ struct bio {
 
 	struct bio_set		*bi_pool;
 
+#ifdef CONFIG_BLK_CGROUP_IOCOST
+	KABI_USE(1, u64 bi_iocost_cost)
+#else
 	KABI_RESERVE(1)
+#endif
 	KABI_RESERVE(2)
 	KABI_RESERVE(3)
 	KABI_RESERVE(4)