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: Ib15ce49ac136da396084ab09972dd132f02beeea
diff --git a/snmp_util.hpp b/snmp_util.hpp
index 2ee7dac..be0c961 100644
--- a/snmp_util.hpp
+++ b/snmp_util.hpp
@@ -44,7 +44,7 @@
  *  @param[in] objPath - D-Bus object path.
  *  @return On success returns the map of name value pair.
  */
-ObjectValueTree getManagedObjects(sdbusplus::bus::bus& bus,
+ObjectValueTree getManagedObjects(sdbusplus::bus_t& bus,
                                   const std::string& service,
                                   const std::string& objPath);