Remove unused function getNumItemsOnDisk from KVShard
Remove unused function getNumItemsOnDisk from KVShard

Change-Id: Ia26a6bf7a4b8e6e33233692e5f0befa6f814d04c
Reviewed-on: http://review.couchbase.org/48757
Reviewed-by: Michael Wiederhold <a17fed27eaa842282862ff7c1b9c8395a26ac320@couchbase.com>
Tested-by: Sriram Ganesan <fde85c3124eed34938bb85159f430bf7e5b650f6@couchbase.com>

teligent-ru/ep-engine,hisundar/ep-engine,daverigby/kv_engine,sriganes/ep-engine,daverigby/kv_engine,hisundar/ep-engine,hisundar/ep-engine,sriganes/ep-engine,daverigby/ep-engine,owendCB/ep-engine,owendCB/ep-engine,sriganes/ep-engine,teligent-ru/ep-engine,daverigby/ep-engine,couchbase/ep-engine,sriganes/ep-engine,membase/ep-engine,membase/ep-engine,teligent-ru/ep-engine,daverigby/kv_engine,daverigby/kv_engine,teligent-ru/ep-engine,owendCB/ep-engine,hisundar/ep-engine,owendCB/ep-engine,daverigby/ep-engine,couchbase/ep-engine,daverigby/ep-engine,couchbase/ep-engine,couchbase/ep-engine,membase/ep-engine,membase/ep-engine