netty client: don't finish parent span (#7126)

Author: amarziali

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/client/HttpClientResponseTracingHandler.java

@@ -71,7 +71,7 @@ public void channelInactive(ChannelHandlerContext ctx) throws Exception {
     parentAttr.setIfAbsent(noopSpan());
     final AgentSpan parent = parentAttr.get();
     final AgentSpan span = ctx.channel().attr(SPAN_ATTRIBUTE_KEY).getAndSet(parent);
-    if (span != null) {
+    if (span != null && span != parent) {
       try (final AgentScope scope = activateSpan(span)) {
         DECORATE.beforeFinish(span);
         span.finish();

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/client/HttpClientResponseTracingHandler.java

@@ -80,7 +80,7 @@ public void channelInactive(ChannelHandlerContext ctx) throws Exception {
     parentAttr.setIfAbsent(noopSpan());
     final AgentSpan parent = parentAttr.get();
     final AgentSpan span = ctx.channel().attr(SPAN_ATTRIBUTE_KEY).getAndSet(parent);
-    if (span != null) {
+    if (span != null && span != parent) {
       try (final AgentScope scope = activateSpan(span)) {
         DECORATE.beforeFinish(span);
         span.finish();