Fix issue jetty#5499

this PR let the ByteAccumulator recyclable. after invoke ByteAccumulator.transferTo method
we can invoke ByteAccumulator.recycle method to reuse byte[] via ByteAccumulator.newByteArray method

Signed-off-by: Baoyi Chen <chen.bao.yi@qq.com>

jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/compress/ByteAccumulator.java

@@ -62,7 +62,7 @@ public void copyChunk(ByteBuffer buffer)
         {
             // release 0 length buffer directly
             if (bufferPool != null)
-                bufferPool.release((ByteBuffer)buffer.clear());
+                bufferPool.release(buffer);
         }
     }
 
@@ -122,7 +122,7 @@ void recycle()
         }
         for (ByteBuffer chunk : chunks)
         {
-            bufferPool.release((ByteBuffer)chunk.clear());
+            bufferPool.release(chunk);
         }
 
         chunks.clear();