selftests: kvm: Fix the segment descriptor layout to match the actual layout

selftests: kvm: Fix the segment descriptor layout to match the actual layout

BugLink: https://bugs.launchpad.net/bugs/1908561
[ Upstream commit df11f7dd5834146defa448acba097e8d7703cc42 ]

Fix the layout of 'struct desc64' to match the layout described in the
SDM Vol 3, Chapter 3 "Protected-Mode Memory Management", section 3.4.5
"Segment Descriptors", Figure 3-8 "Segment Descriptor".  The test added
later in this series relies on this and crashes if this layout is not
correct.

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Message-Id: <20201012194716.3950330-2-aaronlewis@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Ian May <ian.may@canonical.com>