s390/scm: fix virtual vs physical address confusion

[ Upstream commit b1a6a1a77f0666a5a6dc0893ab6ec8fcae46f24c ]

Fix virtual vs physical address confusion (which currently are the same).

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>