sdbusplus: remove deprecated variant_ns

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: If06a676c19b2005c388a6ac48ba2d9f13e7615b2
diff --git a/presence/tach.cpp b/presence/tach.cpp
index a784f94..d8b6395 100644
--- a/presence/tach.cpp
+++ b/presence/tach.cpp
@@ -139,8 +139,7 @@
     auto it = props.find(tachProperty);
     if (it != props.end())
     {
-        std::get<int64_t>(s) =
-            sdbusplus::message::variant_ns::get<int64_t>(it->second);
+        std::get<int64_t>(s) = std::get<int64_t>(it->second);
 
         auto newState = std::any_of(
                 state.begin(),