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: I8c73d8de128b218ee4885a5e133314ad5d9a0ff8
diff --git a/thresholds.hpp b/thresholds.hpp
index 96486d3..2e42938 100644
--- a/thresholds.hpp
+++ b/thresholds.hpp
@@ -10,7 +10,7 @@
 {
 
 template <typename... T>
-using ServerObject = typename sdbusplus::server::object::object<T...>;
+using ServerObject = typename sdbusplus::server::object_t<T...>;
 
 namespace threshold_ns =
     sdbusplus::xyz::openbmc_project::Sensor::Threshold::server;