MB-100 Remove unused variable from BackfillDiskLoad::callback()
MB-100 Remove unused variable from BackfillDiskLoad::callback()

Change-Id: I70879cbdd8ca40f4d6bc0c39f28eddb47968ad8e
Reviewed-on: http://review.couchbase.org/16111
Reviewed-by: Jin Lim <c45cd80a556f432a3607171a6818cd5a074b5cd4@couchbase.com>
Tested-by: Jin Lim <c45cd80a556f432a3607171a6818cd5a074b5cd4@couchbase.com>

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