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: I0eb22958103519924e336a2260a4d48015848c3e
diff --git a/vpd-manager/bios_handler.hpp b/vpd-manager/bios_handler.hpp
index 964fff5..0bc381a 100644
--- a/vpd-manager/bios_handler.hpp
+++ b/vpd-manager/bios_handler.hpp
@@ -55,7 +55,7 @@
     BiosHandler& operator=(BiosHandler&&) = delete;
     ~BiosHandler() = default;
 
-    BiosHandler(sdbusplus::bus::bus& bus, Manager& manager) :
+    BiosHandler(sdbusplus::bus_t& bus, Manager& manager) :
         bus(bus), manager(manager)
     {
         checkAndListenPLDMService();
@@ -89,7 +89,7 @@
      * yes, it will update the VPD with the new attribute value.
      * @param[in] msg - The callback message.
      */
-    void biosAttribsCallback(sdbusplus::message::message& msg);
+    void biosAttribsCallback(sdbusplus::message_t& msg);
 
     /**
      * @brief Persistently saves the Memory mirror mode
@@ -161,7 +161,7 @@
     /**
      * @brief Reference to the bus.
      */
-    sdbusplus::bus::bus& bus;
+    sdbusplus::bus_t& bus;
 
     /**
      * @brief Reference to the manager.