Calling error_report() in a function that takes an Error ** argument
is suspicious.  ioapic_realize() does that, and then exit()s.
Currently mostly harmless, as the device cannot be hot-plugged.

Fixes: 20fd4b7b
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20181017082702.5581-11-armbru@redhat.com>