nVMX: Check EXIT_QUALIFICATION on VM-Enter failures due to bad guest state

Assert that vmcs.EXIT_QUALIFICATION contains the correct failure code on
failed VM-Enter due to invalid guest state.  Hardcode the expected code
to the default code, '0', rather than passing in the expected code to
minimize churn and boilerplate code, which works for all existing tests.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200424174025.1379-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>