Fix comments after the review

src/cets_dist_blocker.erl

@@ -3,7 +3,7 @@
 %% This module prevents a node from reconnecting, until cleaning activity is
 %% finished. It prevents race conditions.
 %%
-%% This module assume all nodes share the same cookie.
+%% This module assumes all nodes share the same cookie.
 -module(cets_dist_blocker).
 -behaviour(gen_server).
 -include_lib("kernel/include/logger.hrl").
@@ -50,7 +50,8 @@ add_cleaner(CleanerPid) ->
 
 %% @doc Confirm that cleaning is done.
 %%
-%% This function is called by a cleaner after it receives nodedown.
+%% This function should be called by a cleaner when it receives
+%% nodedown and finishes cleaning.
 -spec cleaning_done(pid(), node()) -> ok.
 cleaning_done(CleanerPid, Node) ->
     gen_server:call(?MODULE, {cleaning_done, CleanerPid, Node}).