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: I9f166640fbf9d4ee3fb24b542a73237cdf54f775
diff --git a/util/dbus.cpp b/util/dbus.cpp
index 8878f72..585a07d 100644
--- a/util/dbus.cpp
+++ b/util/dbus.cpp
@@ -331,7 +331,7 @@
 
             // create dbus method
             auto bus = sdbusplus::bus::new_system();
-            sdbusplus::message::message method =
+            sdbusplus::message_t method =
                 bus.new_method_call(service.c_str(), path, interface, function);
 
             // append additional dbus call paramaters