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: Ic68a12ef7c12222b1300981282161c971b561dc1
diff --git a/sd_event_loop.cpp b/sd_event_loop.cpp
index acf5e68..ee3395c 100644
--- a/sd_event_loop.cpp
+++ b/sd_event_loop.cpp
@@ -56,7 +56,7 @@
         return 0;
     }
 
-    sdbusplus::bus::bus bus{ipmid_get_sd_bus_connection()};
+    sdbusplus::bus_t bus{ipmid_get_sd_bus_connection()};
     // Enumerate all VLAN + ETHERNET interfaces
     auto req = bus.new_method_call(MAPPER_BUS_NAME, MAPPER_OBJ, MAPPER_INTF,
                                    "GetSubTree");