sdbusplus: remove deprecated variant_ns

Change-Id: I96964f562c505979ad3a5c6a919c8094ba219da9
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/fail-monitor/monitor.cpp b/fail-monitor/monitor.cpp
index 51eb1f3..2ca61ad 100644
--- a/fail-monitor/monitor.cpp
+++ b/fail-monitor/monitor.cpp
@@ -64,7 +64,7 @@
 
     reply.read(property);
 
-    auto value = sdbusplus::message::variant_ns::get<std::string>(property);
+    auto value = std::get<std::string>(property);
     return (value == FAILED_STATE);
 }