Rework time service to fix time passing offline.

src/core/hle/service/kernel_helpers.cpp

@@ -65,6 +65,9 @@ Kernel::KEvent* ServiceContext::CreateEvent(std::string&& name) {
 }
 
 void ServiceContext::CloseEvent(Kernel::KEvent* event) {
+    if (!event) {
+        return;
+    }
     event->GetReadableEvent().Close();
     event->Close();
 }