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

Change-Id: I2d41abae9cbf4878979966d5509f68e34dacdbba
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/src/inventory_mac.cpp b/src/inventory_mac.cpp
index 6a60990..fb38d72 100644
--- a/src/inventory_mac.cpp
+++ b/src/inventory_mac.cpp
@@ -337,7 +337,7 @@
     }
 }
 
-std::unique_ptr<Runtime> watch(sdbusplus::bus::bus& bus, Manager& m)
+std::unique_ptr<Runtime> watch(sdbusplus::bus_t& bus, Manager& m)
 {
     manager = &m;
     std::ifstream in(configFile);