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: I5055fac459cb021ea94686e058e233bcc476a32d
diff --git a/subprojects/nemora-postd/src/host_manager.cpp b/subprojects/nemora-postd/src/host_manager.cpp
index b27ac21..eb0a2b9 100644
--- a/subprojects/nemora-postd/src/host_manager.cpp
+++ b/subprojects/nemora-postd/src/host_manager.cpp
@@ -39,7 +39,7 @@
     post_poller_ = std::make_unique<std::thread>(post_poller_thread, this);
 }
 
-int HostManager::DbusHandleSignal(sdbusplus::message::message& msg)
+int HostManager::DbusHandleSignal(sdbusplus::message_t& msg)
 {
     log<level::INFO>("Property Changed!");
     std::string msgSensor, busName{POSTCODE_BUSNAME};