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: Id93b8dfb6c81f62647dd56f1ce04c1a4fda4f7f4
diff --git a/src/main.cpp b/src/main.cpp
index d808498..7048dd2 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -57,7 +57,7 @@
     EventPtr eventP{event};
     event = nullptr;
 
-    sdbusplus::bus::bus bus = sdbusplus::bus::new_default();
+    sdbusplus::bus_t bus = sdbusplus::bus::new_default();
     sdbusplus::server::manager_t m{bus, DBUS_OBJECT_NAME};
 
     intfName = DBUS_INTF_NAME + std::to_string(postcodeDataHolderObj.node);