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/certs_manager.hpp b/certs_manager.hpp
index fe35a3f..02ea9bb 100644
--- a/certs_manager.hpp
+++ b/certs_manager.hpp
@@ -63,8 +63,8 @@
      *  @param[in] unit - Unit consumed by this certificate.
      *  @param[in] installPath - Certificate installation path.
      */
-    Manager(sdbusplus::bus::bus& bus, sdeventplus::Event& event,
-            const char* path, CertificateType type, const std::string& unit,
+    Manager(sdbusplus::bus_t& bus, sdeventplus::Event& event, const char* path,
+            CertificateType type, const std::string& unit,
             const std::string& installPath);
 
     /** @brief Implementation for Install
@@ -306,7 +306,7 @@
                              const Certificate* const certToDrop = nullptr);
 
     /** @brief sdbusplus handler */
-    sdbusplus::bus::bus& bus;
+    sdbusplus::bus_t& bus;
 
     // sdevent Event handle
     sdeventplus::Event& event;