s390/mm,ptdump: avoid Kasan vs Memcpy Real markers swapping

---[ Real Memory Copy Area Start ]---
0x001bfffffffff000-0x001c000000000000         4K PTE I
---[ Kasan Shadow Start ]---
---[ Real Memory Copy Area End ]---
0x001c000000000000-0x001c000200000000         8G PMD RW NX
...
---[ Kasan Shadow End ]---

ptdump does a stable sort of markers. Move kasan markers after
memcpy real to avoid swapping.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>