ZOOKEEPER-3341: Remove Superfluous ByteBuffer Duplicate

Author: Beluga Behr <dam6923@gmail.com>

Reviewers: andor@apache.org

Closes #881 from BELUGABEHR/ZOOKEEPER-3341

zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumCnxManager.java

@@ -1192,10 +1192,9 @@ public class QuorumCnxManager {
                     /**
                      * Allocates a new ByteBuffer to receive the message
                      */
-                    byte[] msgArray = new byte[length];
+                    final byte[] msgArray = new byte[length];
                     din.readFully(msgArray, 0, length);
-                    ByteBuffer message = ByteBuffer.wrap(msgArray);
-                    addToRecvQueue(new Message(message.duplicate(), sid));
+                    addToRecvQueue(new Message(ByteBuffer.wrap(msgArray), sid));
                 }
             } catch (Exception e) {
                 LOG.warn("Connection broken for id " + sid + ", my id = "