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: Ic0fe1ed7e19cf114b8666d49d4d670c7d9ec595d
diff --git a/utility.hpp b/utility.hpp
index e2487f6..1311fcb 100644
--- a/utility.hpp
+++ b/utility.hpp
@@ -30,7 +30,7 @@
  * @return The service name
  */
 std::string getService(const std::string& path, const std::string& interface,
-                       sdbusplus::bus::bus& bus);
+                       sdbusplus::bus_t& bus);
 
 /**
  * @brief Read a D-Bus property
@@ -45,7 +45,7 @@
 template <typename T>
 void getProperty(const std::string& interface, const std::string& propertyName,
                  const std::string& path, const std::string& service,
-                 sdbusplus::bus::bus& bus, T& value)
+                 sdbusplus::bus_t& bus, T& value)
 {
     std::variant<T> property;
 
@@ -73,7 +73,7 @@
 template <typename T>
 void setProperty(const std::string& interface, const std::string& propertyName,
                  const std::string& path, const std::string& service,
-                 sdbusplus::bus::bus& bus, T& value)
+                 sdbusplus::bus_t& bus, T& value)
 {
     std::variant<T> propertyValue(value);
 
@@ -92,7 +92,7 @@
  * @param[in] bus - D-Bus object
  */
 template <typename T>
-void powerOff(sdbusplus::bus::bus& bus)
+void powerOff(sdbusplus::bus_t& bus)
 {
     phosphor::logging::report<T>();