sdbusplus: remove deprecated variant_ns

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I62deb24e0fc9784289124cc0fc8a6db2de5d6b98
diff --git a/version.cpp b/version.cpp
index c6e43fc..59d40da 100644
--- a/version.cpp
+++ b/version.cpp
@@ -153,8 +153,7 @@
     {
         if (p.first == "CurrentPowerState")
         {
-            chassisState =
-                sdbusplus::message::variant_ns::get<std::string>(p.second);
+            chassisState = std::get<std::string>(p.second);
         }
     }
     if (chassisState.empty())