Added a couple more assertion to a bg fetch test.
Added a couple more assertion to a bg fetch test.

Change-Id: I38b07562bb776d414da9cf2ec7139c3e3d990101
Reviewed-on: http://review.northscale.com/1903
Reviewed-by: Dustin Sallings <1c08efb9b3965701be9d700d9a6f481f1ffec3ea@spy.net>
Tested-by: Dustin Sallings <1c08efb9b3965701be9d700d9a6f481f1ffec3ea@spy.net>

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