spapr: Simplify error handling in callers of ppc_set_compat()

Now that ppc_set_compat() indicates success/failure with a return
value, use it and reduce error propagation overhead.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-5-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr.c

@@ -3817,10 +3817,9 @@ static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
      */
     if (hotplugged) {
         for (i = 0; i < cc->nr_threads; i++) {
-            ppc_set_compat(core->threads[i], POWERPC_CPU(first_cpu)->compat_pvr,
-                           &local_err);
-            if (local_err) {
-                error_propagate(errp, local_err);
+            if (ppc_set_compat(core->threads[i],
+                               POWERPC_CPU(first_cpu)->compat_pvr,
+                               errp) < 0) {
                 return;
             }
         }