sdbusplus: use shorter type aliases

The sdbusplus headers provide shortened aliases for many types.
Switch to using them to provide better code clarity and shorter
lines.  Possible replacements are for:
  * bus_t
  * exception_t
  * manager_t
  * match_t
  * message_t
  * object_t
  * slot_t

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I41103c892db258a85640aa1442acd9a295c8a847
diff --git a/test/test_scheduled_host_transition.cpp b/test/test_scheduled_host_transition.cpp
index 972248c..76b625a 100644
--- a/test/test_scheduled_host_transition.cpp
+++ b/test/test_scheduled_host_transition.cpp
@@ -26,7 +26,7 @@
   public:
     sdeventplus::Event event;
     sdbusplus::SdBusMock sdbusMock;
-    sdbusplus::bus::bus mockedBus = sdbusplus::get_mocked_new(&sdbusMock);
+    sdbusplus::bus_t mockedBus = sdbusplus::get_mocked_new(&sdbusMock);
     ScheduledHostTransition scheduledHostTransition;
 
     TestScheduledHostTransition() :