hw/intc/xics.c:605: ics_realize: Assertion `ics->xics' failed

[Thomas Huth]

 Hi Greg,

I just ran  scripts/device-crash-test and it triggered the assert that
you've added in commit b015a9809427c8 ("xics: Link ICS_PROP_XICS
property to ICSState::xics pointer"):

$ qemu-system-ppc64 -S -M powernv9,accel=tcg -device pnv-psi-POWER8
qemu-system-ppc64: hw/intc/xics.c:605: ics_realize: Assertion
`ics->xics' failed.
Aborted (core dumped)

That's ugly. Could you please have a look how this could be done in a
nicer way? (Maybe set errp and return in that case?)

 Thanks,
  Thomas