[VOL-3141] Created Span for various Openflow and Ofagent operations

Change-Id: I49e371479edc087dcf89bd60b43c000ab0bb5547
diff --git a/internal/pkg/ofagent/changeEvent.go b/internal/pkg/ofagent/changeEvent.go
index 7ec9aae..3f5bb7f 100644
--- a/internal/pkg/ofagent/changeEvent.go
+++ b/internal/pkg/ofagent/changeEvent.go
@@ -29,6 +29,9 @@
 )
 
 func (ofa *OFAgent) receiveChangeEvents(ctx context.Context) {
+	span, ctx := log.CreateChildSpan(ctx, "receive-change-events")
+	defer span.Finish()
+
 	logger.Debug(ctx, "receive-change-events-started")
 	// If we exit, assume disconnected
 	defer func() {