sdbusplus: remove deprecated variant_ns

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I3c785d33984b7c3af8671432c194db34be360b52
diff --git a/utility.hpp b/utility.hpp
index 0f008e3..26968ec 100644
--- a/utility.hpp
+++ b/utility.hpp
@@ -56,7 +56,7 @@
     auto reply = bus.call(method);
 
     reply.read(property);
-    value = sdbusplus::message::variant_ns::get<T>(property);
+    value = std::get<T>(property);
 }
 
 /**