Correct CloseHandle() call.

Closing a service handle is done with CloseHandle() not
CloseServiceHandle().

service.cpp

@@ -528,7 +528,7 @@ void cleanup_nssm_service(nssm_service_t *service) {
   }
   if (service->env) HeapFree(GetProcessHeap(), 0, service->env);
   if (service->env_extra) HeapFree(GetProcessHeap(), 0, service->env_extra);
-  if (service->handle) CloseServiceHandle(service->handle);
+  if (service->handle) CloseHandle(service->handle);
   if (service->process_handle) CloseHandle(service->process_handle);
   if (service->wait_handle) UnregisterWait(service->process_handle);
   if (service->throttle_section_initialised) DeleteCriticalSection(&service->throttle_section);