Clarify rebar_utils:ensure_dir/1 comment

src/rebar_utils.erl

@@ -112,7 +112,8 @@ now_str() ->
     lists:flatten(io_lib:format("~4b/~2..0b/~2..0b ~2..0b:~2..0b:~2..0b",
 				[Year, Month, Day, Hour, Minute, Second])).
 
-%% TODO: filelib:ensure_dir/1 corrected in R13B04. Can be removed.
+%% TODO: filelib:ensure_dir/1 corrected in R13B04. Remove when we drop
+%% support for OTP releases older than R13B04.
 ensure_dir(Path) ->
     case filelib:ensure_dir(Path) of
         ok ->