KVM: nVMX: Make an event request if INIT or SIPI is pending on VM-Enter

Evaluate interrupts, i.e. set KVM_REQ_EVENT, if INIT or SIPI is pending
when emulating nested VM-Enter.  INIT is blocked while the CPU is in VMX
root mode, but not in VMX non-root, i.e. becomes unblocked on VM-Enter.
This bug has been masked by KVM calling ->check_nested_events() in the
core run loop, but that hack will be fixed in the near future.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220921003201.1441511-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>