sdbusplus: remove deprecated variant_ns

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I691cbbfce8a74873be6bab8f11fad2dd335bb742
diff --git a/ext_interface.cpp b/ext_interface.cpp
index 5ce66c2..f37eab6 100644
--- a/ext_interface.cpp
+++ b/ext_interface.cpp
@@ -78,5 +78,5 @@
     sdbusplus::message::variant<uint32_t> rebootCount;
     reply.read(rebootCount);
 
-    return sdbusplus::message::variant_ns::get<uint32_t>(rebootCount);
+    return std::get<uint32_t>(rebootCount);
 }