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: If9a7314dade153dd7dbd149a76352aca8257839d
diff --git a/ubi/activation_ubi.cpp b/ubi/activation_ubi.cpp
index 946a741..205c393 100644
--- a/ubi/activation_ubi.cpp
+++ b/ubi/activation_ubi.cpp
@@ -129,7 +129,7 @@
     activationProgress->progress(10);
 }
 
-void ActivationUbi::unitStateChange(sdbusplus::message::message& msg)
+void ActivationUbi::unitStateChange(sdbusplus::message_t& msg)
 {
     uint32_t newStateID{};
     sdbusplus::message::object_path newStateObjPath;