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: I9cedddf4dc9b224ecbc2f68e6b00c0ab1885a826
diff --git a/test/TestBmcEpoch.cpp b/test/TestBmcEpoch.cpp
index 651e019..a5fdb33 100644
--- a/test/TestBmcEpoch.cpp
+++ b/test/TestBmcEpoch.cpp
@@ -19,7 +19,7 @@
 class TestBmcEpoch : public testing::Test
 {
   public:
-    sdbusplus::bus::bus bus;
+    sdbusplus::bus_t bus;
     sd_event* event;
     std::unique_ptr<BmcEpoch> bmcEpoch;
 
diff --git a/test/TestManager.cpp b/test/TestManager.cpp
index db36b42..b879d3a 100644
--- a/test/TestManager.cpp
+++ b/test/TestManager.cpp
@@ -16,7 +16,7 @@
 class TestManager : public testing::Test
 {
   public:
-    sdbusplus::bus::bus bus;
+    sdbusplus::bus_t bus;
     Manager manager;
 
     TestManager() : bus(sdbusplus::bus::new_default()), manager(bus)