Remove unnecessary maybe_map/1

Thought slightly harder and realized this was unnecessary.

src/jiffy.erl

@@ -137,7 +137,7 @@ finish_decode({Pairs}) when is_list(Pairs) ->
 finish_decode(Vals) when is_list(Vals) ->
     finish_decode_arr(Vals, []);
 finish_decode({has_trailer, Value, Rest}) ->
-    {has_trailer, maybe_map(finish_decode(Value)), Rest};
+    {has_trailer, finish_decode(Value), Rest};
 finish_decode(Val) ->
     maybe_map(Val).