cpus: kvm: unregister thread with RCU

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/cpus.c b/cpus.c
index 08a8462..1063dac 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1205,6 +1205,7 @@
     cpu->created = false;
     qemu_cond_signal(&qemu_cpu_cond);
     qemu_mutex_unlock_iothread();
+    rcu_unregister_thread();
     return NULL;
 }