s390x: fix cpu object referrence leak in s390x_new_cpu()

object_new() returns cpu with refcnt == 1 and after realize
refcnt == 2*. s390x_new_cpu() as an owner of the first refcnt
should have released it on exit in both cases (on error and
success) to avoid it leaking. Do so for both cases.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Message-Id: <1508247680-98800-2-git-send-email-imammedo@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

target/s390x/helper.c

@@ -73,9 +73,9 @@ S390CPU *s390x_new_cpu(const char *typename, uint32_t core_id, Error **errp)
     object_property_set_bool(OBJECT(cpu), true, "realized", &err);
 
 out:
+    object_unref(OBJECT(cpu));
     if (err) {
         error_propagate(errp, err);
-        object_unref(OBJECT(cpu));
         cpu = NULL;
     }
     return cpu;