iommu/amd: Clean up the cmpxchg64 invocation

Change it as it's designed for and keep it consistent with other
places.

Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Baoquan He 2016-09-15 16:50:50 +08:00 • committed by Joerg Roedel
commit 134414fffc