sdbusplus: remove deprecated variant_ns

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I40c4c90fcebf4c984201653a1ac4d6f203d82eb2
diff --git a/hiomap.cpp b/hiomap.cpp
index d29a0cb..8e714e7 100644
--- a/hiomap.cpp
+++ b/hiomap.cpp
@@ -364,7 +364,7 @@
         }
 
         uint8_t mask = ctx->event_lookup[x.first];
-        auto value = sdbusplus::message::variant_ns::get<bool>(x.second);
+        auto value = std::get<bool>(x.second);
 
         if (value)
         {