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: Ibd2a0b512bfb7caf65bfab64b271d194da520aac
diff --git a/user_channel/channel_mgmt.hpp b/user_channel/channel_mgmt.hpp
index 0f35816..9b03063 100644
--- a/user_channel/channel_mgmt.hpp
+++ b/user_channel/channel_mgmt.hpp
@@ -252,7 +252,7 @@
     std::time_t nvFileLastUpdatedTime;
     std::time_t voltFileLastUpdatedTime;
     boost::interprocess::file_lock mutexCleanupLock;
-    sdbusplus::bus::bus bus;
+    sdbusplus::bus_t bus;
     bool signalHndlrObjectState = false;
     boost::interprocess::file_lock sigHndlrLock;