Fix build failure

Comparing strings to object paths directly isn't supported
at the moment.

Change-Id: I98083cf563fe8dde74e7f058720a0481bbe7c2e6
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/test/test.cpp b/test/test.cpp
index 89e46b9..28fa611 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -163,7 +163,7 @@
         sdbusplus::message::object_path signalPath;
         Object<std::string> signalObject;
         sig.read(signalPath);
-        assert(path == signalPath);
+        assert(path == signalPath.str);
         sig.read(signalObject);
         assert(hasProperties(signalObject, obj));
         auto moreSignals{queue.pop()};