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: I7ae6214461bdf45c1a21fb702cc8bf5578d827c6
diff --git a/dump-extensions/default/default.cpp b/dump-extensions/default/default.cpp
index 184ab14..0de4e09 100644
--- a/dump-extensions/default/default.cpp
+++ b/dump-extensions/default/default.cpp
@@ -4,7 +4,7 @@
 {
 namespace dump
 {
-void loadExtensions(sdbusplus::bus::bus&, DumpManagerList&)
+void loadExtensions(sdbusplus::bus_t&, DumpManagerList&)
 {}
 } // namespace dump
 } // namespace phosphor