core+daemon: eliminate scheduler::{schedule,cancel} wrappers

Also move core/global-io.hpp to daemon/global.hpp

Refs: #4528, #4883
Change-Id: I0b99029f1a19d7451aab57099cd3303b7eb42ff3
diff --git a/tests/daemon/face/channel-fixture.hpp b/tests/daemon/face/channel-fixture.hpp
index 7efedfd..8f94a09 100644
--- a/tests/daemon/face/channel-fixture.hpp
+++ b/tests/daemon/face/channel-fixture.hpp
@@ -27,7 +27,8 @@
 #define NFD_TESTS_DAEMON_FACE_CHANNEL_FIXTURE_HPP
 
 #include "face/channel.hpp"
-#include "tests/limited-io.hpp"
+
+#include "tests/daemon/limited-io.hpp"
 
 #include <type_traits>