qemu: Use maximum guest memory size when getting NUMA placement advice

When starting the VM the guest balloon driver is not loaded at that
time. We need to ask numad for placement of the complete VM.

src/qemu/qemu_process.c

@@ -3684,7 +3684,7 @@ int qemuProcessStart(virConnectPtr conn,
         (vm->def->numatune.memory.placement_mode ==
          VIR_NUMA_TUNE_MEM_PLACEMENT_MODE_AUTO)) {
         nodeset = virNumaGetAutoPlacementAdvice(vm->def->vcpus,
-                                                vm->def->mem.cur_balloon);
+                                                vm->def->mem.max_balloon);
         if (!nodeset)
             goto cleanup;