qemu: process: Enforce 'vcpu' order range to <1,maxvcpus>

The current code that validates duplicate vcpu order would not work
properly if the order would exceed def->maxvcpus. Limit the order to the
interval described.

src/qemu/qemu_process.c

@@ -4811,10 +4811,14 @@ qemuProcessValidateHotpluggableVcpus(virDomainDefPtr def)
                 goto cleanup;
             }
 
-            ignore_value(virBitmapSetBit(ordermap, vcpu->order));
+            if (virBitmapSetBit(ordermap, vcpu->order)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("vcpu order '%u' exceeds vcpu count"),
+                               vcpu->order);
+                goto cleanup;
+            }
         }
 
-
         for (j = i + 1; j < (i + vcpupriv->vcpus); j++) {
             subvcpu = virDomainDefGetVcpu(def, j);
             if (subvcpu->hotpluggable != vcpu->hotpluggable ||