Fix dialyzer warnings from riak_cs_list_objects_fsm_v2
Fix dialyzer warnings from riak_cs_list_objects_fsm_v2

basho/riak_cs,yangchengjian/riak_cs,yangchengjian/riak_cs,laurenrother/riak_cs,sdebnath/riak_cs,GabrielNicolasAvellaneda/riak_cs,basho/riak_cs,sdebnath/riak_cs,laurenrother/riak_cs,dragonfax/riak_cs,yangchengjian/riak_cs,dragonfax/riak_cs,basho/riak_cs,sdebnath/riak_cs,basho/riak_cs,sdebnath/riak_cs,dragonfax/riak_cs,laurenrother/riak_cs,GabrielNicolasAvellaneda/riak_cs,laurenrother/riak_cs,dragonfax/riak_cs,yangchengjian/riak_cs,GabrielNicolasAvellaneda/riak_cs,GabrielNicolasAvellaneda/riak_cs