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: I9bb7b9a430d029ddaf2a08ea26acb775b9b2b152
diff --git a/test/certs_manager_test.cpp b/test/certs_manager_test.cpp
index b3a1563..6ab7ae9 100644
--- a/test/certs_manager_test.cpp
+++ b/test/certs_manager_test.cpp
@@ -204,7 +204,7 @@
     }
 
   protected:
-    sdbusplus::bus::bus bus;
+    sdbusplus::bus_t bus;
     std::string certificateFile, CSRFile, privateKeyFile, rsaPrivateKeyFilePath;
 
     std::string certDir;
@@ -260,7 +260,7 @@
   public:
     static constexpr std::string_view unitToRestartInTest =
         "xyz.openbmc_project.awesome-service";
-    ManagerInTest(sdbusplus::bus::bus& bus, sdeventplus::Event& event,
+    ManagerInTest(sdbusplus::bus_t& bus, sdeventplus::Event& event,
                   const char* path, CertificateType type,
                   const std::string& unit, const std::string& installPath) :
         Manager(bus, event, path, type, unit, installPath)
@@ -898,7 +898,7 @@
     }
 
   protected:
-    sdbusplus::bus::bus bus;
+    sdbusplus::bus_t bus;
     std::string certificateFile;
     std::string keyFile;
     std::string certDir;
@@ -1599,7 +1599,7 @@
         });
     };
 
-    sdbusplus::bus::bus bus;
+    sdbusplus::bus_t bus;
     fs::path authoritiesListFolder;
     fs::path sourceAuthoritiesListFile;
 };