Corrected statname for bucket's memquota
Corrected statname for bucket's memquota

- Using cbepctl for setting mem_low_wat,
and mem_high_wat breaks because ep_max_data_size
is used for bucket's memory quota which doesn't
exist anymore.
- Corrected stat: ep_max_size

Change-Id: If22ec8f43015c9fd87ad50674704a18089a7ee60
Reviewed-on: http://review.couchbase.org/32892
Reviewed-by: Chiyoung Seo <fcffc23db27b19ee4ebba46695ee6b50e09216a2@couchbase.com>
Tested-by: abhinav dangeti <d73ef2279de6577f7bf081737ee47554bbb7dc82@couchbase.com>

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