Fix specs.

src/syn.erl

@@ -55,11 +55,11 @@ stop() ->
 init() ->
     ok = syn_backbone:initdb().
 
--spec register(Key :: any(), Pid :: pid()) -> ok | {error, taken}.
+-spec register(Key :: any(), Pid :: pid()) -> ok | {error, taken | pid_already_registered}.
 register(Key, Pid) ->
     syn_backbone:register(Key, Pid).
 
--spec register(Key :: any(), Pid :: pid(), Meta :: any()) -> ok | {error, taken}.
+-spec register(Key :: any(), Pid :: pid(), Meta :: any()) -> ok | {error, taken | pid_already_registered}.
 register(Key, Pid, Meta) ->
     syn_backbone:register(Key, Pid, Meta).
 

src/syn_consistency.erl

@@ -166,7 +166,7 @@ code_change(_OldVsn, State, _Extra) ->
 %% ===================================================================
 %% Internal
 %% ===================================================================
--spec delete_pids_of_disconnected_node(RemoteNode :: atom()) -> pid().
+-spec delete_pids_of_disconnected_node(RemoteNode :: atom()) -> ok.
 delete_pids_of_disconnected_node(RemoteNode) ->
     %% build match specs
     MatchHead = #syn_processes_table{key = '$1', node = '$2', _ = '_'},