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/csr.hpp b/csr.hpp
index eb02df6..05d5ba6 100644
--- a/csr.hpp
+++ b/csr.hpp
@@ -37,7 +37,7 @@
      *  @param[in] installPath - Certificate installation path.
      *  @param[in] status - Status of Generate CSR request
      */
-    CSR(sdbusplus::bus::bus& bus, const char* path, std::string&& installPath,
+    CSR(sdbusplus::bus_t& bus, const char* path, std::string&& installPath,
         const Status& status);
     /** @brief Return CSR
      */