Fix to the memory leak in replicating items through the checkpoint.
Fix to the memory leak in replicating items through the checkpoint.

There was a memory leak caused by creating an GetValue instance
without returning it to the memcached thread. For items that are
fetched from the checkpoint, we do not need to create GetValue
instances.

Change-Id: Ia6fbf537ca5a03b3c1aef3c496cd28e3ea3ac37b
Reviewed-on: http://review.membase.org/5112
Tested-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>

jimwwalker/ep-engine,zbase/ep-engine,sriganes/ep-engine,couchbaselabs/ep-engine,abhinavdangeti/ep-engine,jimwwalker/ep-engine,abhinavdangeti/ep-engine,teligent-ru/ep-engine,couchbaselabs/ep-engine,couchbaselabs/ep-engine,daverigby/kv_engine,membase/ep-engine,hisundar/ep-engine,teligent-ru/ep-engine,sriganes/ep-engine,abhinavdangeti/ep-engine,membase/ep-engine,hisundar/ep-engine,daverigby/kv_engine,daverigby/kv_engine,owendCB/ep-engine,sriganes/ep-engine,hisundar/ep-engine,teligent-ru/ep-engine,daverigby/ep-engine,zbase/ep-engine,couchbase/ep-engine,jimwwalker/ep-engine,daverigby/ep-engine,zbase/ep-engine,abhinavdangeti/ep-engine,zbase/ep-engine,daverigby/kv_engine,couchbase/ep-engine,sriganes/ep-engine,hisundar/ep-engine,abhinavdangeti/ep-engine,membase/ep-engine,couchbase/ep-engine,couchbase/ep-engine,teligent-ru/ep-engine,owendCB/ep-engine,daverigby/ep-engine,daverigby/ep-engine,jimwwalker/ep-engine,couchbaselabs/ep-engine,owendCB/ep-engine,owendCB/ep-engine,couchbaselabs/ep-engine,zbase/ep-engine,membase/ep-engine