KVM: Don't mistreat edge-triggered INIT IPI as INIT de-assert. (LAPIC)
If the guest programs an IPI with level=0 (de-assert) and trig_mode=0 (edge),
it is erroneously treated as INIT de-assert and ignored, but to quote the
spec: "For this delivery mode [INIT de-assert], the level flag must be set to
0 and trigger mode flag to 1."