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: Ie530f2c63000bbfac7c5fbbc74ebe6bc8c07fb1a
diff --git a/test/test_utils.cpp b/test/test_utils.cpp
index afcbb47..668803e 100644
--- a/test/test_utils.cpp
+++ b/test/test_utils.cpp
@@ -23,7 +23,7 @@
 
     EXPECT_CALL(sdbusMock, sd_bus_message_ref(IsNull()))
         .WillOnce(Return(nullptr));
-    sdbusplus::message::message msg(nullptr, &sdbusMock);
+    sdbusplus::message_t msg(nullptr, &sdbusMock);
 
     const char* path0 = "/com/example/chassis/powersupply0";
     const char* path1 = "/com/example/chassis/powersupply1";