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: I6a559082fed34ae62b648345ead793436d2d03f6
diff --git a/src/main.cpp b/src/main.cpp
index 2686056..84bad44 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -31,7 +31,7 @@
     auto& bus = SDBusPlus::getBus();
 
     // Add sdbusplus Object Manager for the 'root' path of events.
-    sdbusplus::server::manager::manager objManager(bus, OBJ_EVENT);
+    sdbusplus::server::manager_t objManager(bus, OBJ_EVENT);
 
     phosphor::events::getManager().restore();