qemu-timer: do not refer to runstate_is_running()

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/cpus.c b/cpus.c
index 21538e6..1328baa 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1059,6 +1059,7 @@
 {
     CPUState *penv = first_cpu;
 
+    qemu_clock_enable(vm_clock, false);
     while (penv) {
         penv->stop = 1;
         qemu_cpu_kick(penv);