Fixed locking.

Signed-off-by: Simone Bordet <simone.bordet@gmail.com>

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/HTTP2Stream.java

@@ -769,7 +769,7 @@ public class HTTP2Stream implements IStream, Callback, Dumpable, CyclicTimeouts.
     @Override
     public InvocationType getInvocationType()
     {
-        synchronized (this)
+        try (AutoLock ignored = lock.lock())
         {
             return sendCallback != null ? sendCallback.getInvocationType() : Callback.super.getInvocationType();
         }