Fix resource leak in LengthFieldBasedFrameDecoderTest

codec/src/test/java/io/netty/handler/codec/frame/LengthFieldBasedFrameDecoderTest.java

@@ -44,6 +44,7 @@ public class LengthFieldBasedFrameDecoderTest {
             ch.writeInbound(Unpooled.wrappedBuffer(new byte[] { 0, 0, 0, 1, 'A' }));
             ByteBuf buf = (ByteBuf) ch.readInbound();
             assertEquals("A", buf.toString(CharsetUtil.ISO_8859_1));
+            buf.release();
         }
     }