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.cpp b/handler.cpp
index bc8f9bd..a82c401 100644
--- a/handler.cpp
+++ b/handler.cpp
@@ -437,7 +437,7 @@
 
 } // namespace
 
-sdbusplus::bus::bus Handler::getDbus() const
+sdbusplus::bus_t Handler::getDbus() const
 {
     return sdbusplus::bus::new_default();
 }