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: I91502c85799b7d3be22b7d05659ff26bea08c32b
diff --git a/inc/button_factory.hpp b/inc/button_factory.hpp
index fc75f4f..69e05a9 100644
--- a/inc/button_factory.hpp
+++ b/inc/button_factory.hpp
@@ -8,7 +8,7 @@
 #include <unordered_map>
 
 using buttonIfCreatorMethod = std::function<std::unique_ptr<ButtonIface>(
-    sdbusplus::bus::bus& bus, EventPtr& event, buttonConfig& buttonCfg)>;
+    sdbusplus::bus_t& bus, EventPtr& event, buttonConfig& buttonCfg)>;
 
 /**
  * @brief This is abstract factory for the creating phosphor buttons objects
@@ -36,7 +36,7 @@
     void addToRegistry()
     {
         buttonIfaceRegistry[std::string(T::getFormFactorName())] =
-            [](sdbusplus::bus::bus& bus, EventPtr& event,
+            [](sdbusplus::bus_t& bus, EventPtr& event,
                buttonConfig& buttonCfg) {
                 return std::make_unique<T>(bus, T::getDbusObjectPath(), event,
                                            buttonCfg);
@@ -47,7 +47,7 @@
      *    corresponding to the button formfactor name provided
      */
     std::unique_ptr<ButtonIface> createInstance(const std::string& name,
-                                                sdbusplus::bus::bus& bus,
+                                                sdbusplus::bus_t& bus,
                                                 EventPtr& event,
                                                 buttonConfig& buttonCfg)
     {