Fix infinite loop in transport worker

Summary:
Fix transport workers looping over and over instead of hibernating when
no work is available.

Reviewed By: RunyaoZhang

Differential Revision: D65697233

fbshipit-source-id: 7fb1453815ea98784457104e57830b72957ab1b0

src/wa_raft_transport_worker.erl

@@ -105,7 +105,7 @@ handle_cast(Request, #state{number = Number} = State) ->
 handle_info(timeout, #state{number = Number, jobs = Jobs, states = States} = State) ->
     case queue:out(Jobs) of
         {empty, NewJobs} ->
-            {noreply, State#state{jobs = NewJobs}, ?CONTINUE_TIMEOUT};
+            {noreply, State#state{jobs = NewJobs}, hibernate};
         {{value, #transport{id = ID}}, NewJobs} ->
             case wa_raft_transport:pop_file(ID) of
                 {ok, FileID} ->