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: Ibc25db433a6926f7ee43ea83312c3ac14f480c33
diff --git a/test/serialization_tests.hpp b/test/serialization_tests.hpp
index 902ddf3..c92237a 100644
--- a/test/serialization_tests.hpp
+++ b/test/serialization_tests.hpp
@@ -21,7 +21,7 @@
 
 char tmplt[] = "/tmp/logging_test.XXXXXX";
 sdbusplus::SdBusMock sdbusMock;
-sdbusplus::bus::bus bus = sdbusplus::get_mocked_new(&sdbusMock);
+sdbusplus::bus_t bus = sdbusplus::get_mocked_new(&sdbusMock);
 phosphor::logging::internal::Manager manager(bus, OBJ_INTERNAL);
 
 class TestSerialization : public testing::Test