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

Change-Id: I9be2bd75eae5c5098b6206b900b9956e764cf03a
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/oem/ibm/test/host_bmc_lamp_test.cpp b/oem/ibm/test/host_bmc_lamp_test.cpp
index 7d75649..26dc4fc 100644
--- a/oem/ibm/test/host_bmc_lamp_test.cpp
+++ b/oem/ibm/test/host_bmc_lamp_test.cpp
@@ -15,7 +15,7 @@
 class MockLampTest : public HostLampTest
 {
   public:
-    MockLampTest(sdbusplus::bus::bus& bus, const std::string& objPath,
+    MockLampTest(sdbusplus::bus_t& bus, const std::string& objPath,
                  uint8_t mctp_eid, pldm::InstanceIdDb& instanceIdDb,
                  pldm_pdr* repo,
                  pldm::requester::Handler<pldm::requester::Request>* handler) :
@@ -29,7 +29,7 @@
 
 TEST(TestLamp, Asserted)
 {
-    sdbusplus::bus::bus bus = sdbusplus::bus::new_default();
+    sdbusplus::bus_t bus = sdbusplus::bus::new_default();
     TestInstanceIdDb instanceIdDb;
 
     MockLampTest lampTest(bus, "/xyz/openbmc_project/led/groups/host_lamp_test",