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: I9029cc722e7712633c15436bd3868d8c3209f567
diff --git a/control/fan.hpp b/control/fan.hpp
index f686817..de0a85c 100644
--- a/control/fan.hpp
+++ b/control/fan.hpp
@@ -36,7 +36,7 @@
      * @param[in] bus - the dbus object
      * @param[in] def - the fan definition data
      */
-    Fan(sdbusplus::bus::bus& bus, const FanDefinition& def);
+    Fan(sdbusplus::bus_t& bus, const FanDefinition& def);
 
     /**
      * Sets the speed value on all contained sensors
@@ -59,7 +59,7 @@
     /**
      * The dbus object
      */
-    sdbusplus::bus::bus& _bus;
+    sdbusplus::bus_t& _bus;
 
     /**
      * The inventory name of the fan