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: I41103c892db258a85640aa1442acd9a295c8a847
diff --git a/bmc_state_manager_main.cpp b/bmc_state_manager_main.cpp
index 5867e51..1d6f617 100644
--- a/bmc_state_manager_main.cpp
+++ b/bmc_state_manager_main.cpp
@@ -13,7 +13,7 @@
     auto objPathInst = std::string(BMC_OBJPATH) + '0';
 
     // Add sdbusplus ObjectManager.
-    sdbusplus::server::manager::manager objManager(bus, objPathInst.c_str());
+    sdbusplus::server::manager_t objManager(bus, objPathInst.c_str());
 
     phosphor::state::manager::BMC manager(bus, objPathInst.c_str());