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: Ie7375047bd567aa052d3bd35a6dd7008779a05b4
diff --git a/src/bridgingcommands.cpp b/src/bridgingcommands.cpp
index c110563..f6fc02f 100644
--- a/src/bridgingcommands.cpp
+++ b/src/bridgingcommands.cpp
@@ -192,7 +192,7 @@
                             (ipmbResponseDataHeaderLength + data.size()));
 }
 
-void IpmbRequest::prepareRequest(sdbusplus::message::message& mesg)
+void IpmbRequest::prepareRequest(sdbusplus::message_t& mesg)
 {
     mesg.append(ipmbMeChannelNum, netFn, rqLun, cmd, data);
 }
@@ -592,7 +592,7 @@
             getMsgFlagsRes.set(getMsgFlagWatchdogPreTimeOutBit);
         }
     }
-    catch (const sdbusplus::exception::exception& e)
+    catch (const sdbusplus::exception_t& e)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(
             "ipmiAppGetMessageFlags, dbus call exception");
@@ -667,7 +667,7 @@
                                   wdtInterruptFlagProp, false);
         }
     }
-    catch (const sdbusplus::exception::exception& e)
+    catch (const sdbusplus::exception_t& e)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(
             "ipmiAppClearMessageFlags: can't Clear/Set "