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

Change-Id: Ie3b9c52f1fe18c89432ee7eb5d8023e028565541
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/handler_impl.hpp b/handler_impl.hpp
index 33e5592..b4e87c6 100644
--- a/handler_impl.hpp
+++ b/handler_impl.hpp
@@ -72,7 +72,7 @@
 
   protected:
     // Exposed for dependency injection
-    virtual sdbusplus::bus::bus getDbus() const;
+    virtual sdbusplus::bus_t getDbus() const;
 
   private:
     std::string _configFile;