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: Ie36d234f4580029a7832a0cd179f3bb78a1a403f
diff --git a/dbus/dbushelper.cpp b/dbus/dbushelper.cpp
index d08f537..01383cb 100644
--- a/dbus/dbushelper.cpp
+++ b/dbus/dbushelper.cpp
@@ -58,7 +58,7 @@
 
         responseMsg.read(response);
     }
-    catch (const sdbusplus::exception::exception& ex)
+    catch (const sdbusplus::exception_t& ex)
     {
         log<level::ERR>("ObjectMapper call failure",
                         entry("WHAT=%s", ex.what()));
@@ -88,7 +88,7 @@
         auto valueResponseMsg = _bus.call(pimMsg);
         valueResponseMsg.read(propMap);
     }
-    catch (const sdbusplus::exception::exception& ex)
+    catch (const sdbusplus::exception_t& ex)
     {
         log<level::ERR>("GetAll Properties Failed",
                         entry("WHAT=%s", ex.what()));
@@ -135,7 +135,7 @@
     {
         getProperty(service, path, availabilityIntf, "Available", available);
     }
-    catch (const sdbusplus::exception::exception& ex)
+    catch (const sdbusplus::exception_t& ex)
     {
         // unsupported Available property, leaving reading at 'True'
     }