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: Ief05bd757cffb1453e058a719ee4b060861752e7
diff --git a/phosphor-regulators/src/services.hpp b/phosphor-regulators/src/services.hpp
index 07e3d5f..3c2e3ff 100644
--- a/phosphor-regulators/src/services.hpp
+++ b/phosphor-regulators/src/services.hpp
@@ -52,7 +52,7 @@
      *
      * @return D-Bus bus
      */
-    virtual sdbusplus::bus::bus& getBus() = 0;
+    virtual sdbusplus::bus_t& getBus() = 0;
 
     /**
      * Returns the error logging interface.
@@ -111,13 +111,13 @@
      *
      * @param bus D-Bus bus object
      */
-    explicit BMCServices(sdbusplus::bus::bus& bus) :
+    explicit BMCServices(sdbusplus::bus_t& bus) :
         bus{bus}, errorLogging{bus},
         presenceService{bus}, sensors{bus}, vpd{bus}
     {}
 
     /** @copydoc Services::getBus() */
-    virtual sdbusplus::bus::bus& getBus() override
+    virtual sdbusplus::bus_t& getBus() override
     {
         return bus;
     }
@@ -156,7 +156,7 @@
     /**
      * D-Bus bus object.
      */
-    sdbusplus::bus::bus& bus;
+    sdbusplus::bus_t& bus;
 
     /**
      * Implementation of the ErrorLogging interface using D-Bus method calls.