s390x/event-facility: Fix realize() error API violations

sclp_events_bus_realize() dereferences @errp when
object_property_set_bool() fails.  That's wrong; see the big comment
in error.h.  Introduced in commit f6102c329c "s390/sclp: rework sclp
event facility initialization + device realization".

No caller actually passes null.

Fix anyway: splice in a local Error *err, and error_propagate().

Cc: David Hildenbrand <david@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20191204093625.14836-12-armbru@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
index 66205697ae..cdcf9154c4 100644
--- a/hw/s390x/event-facility.c
+++ b/hw/s390x/event-facility.c
@@ -339,14 +339,16 @@ out:
 
 static void sclp_events_bus_realize(BusState *bus, Error **errp)
 {
+    Error *err = NULL;
     BusChild *kid;
 
     /* TODO: recursive realization has to be done in common code */
     QTAILQ_FOREACH(kid, &bus->children, sibling) {
         DeviceState *dev = kid->child;
 
-        object_property_set_bool(OBJECT(dev), true, "realized", errp);
-        if (*errp) {
+        object_property_set_bool(OBJECT(dev), true, "realized", &err);
+        if (errp) {
+            error_propagate(errp, err);
             return;
         }
     }