KVM: selftests: Replace hardcoded Linux OS id with HYPERV_LINUX_OS_ID

Use HYPERV_LINUX_OS_ID macro instead of hardcoded 0x8100 << 48

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20221212183720.4062037-12-vipinsh@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>