fix(dialyzer): incorrect function spec

apps/emqx_resource/rebar.config

@@ -1,6 +1,6 @@
 {erl_opts, [ debug_info
            , nowarn_unused_import
-           , {d, 'RESOURCE_DEBUG'}
+           %, {d, 'RESOURCE_DEBUG'}
            ]}.
 
 {erl_first_files, ["src/emqx_resource_transform.erl"]}.

apps/emqx_resource/src/emqx_resource.erl

@@ -223,7 +223,7 @@ load_instances_from_dir(Dir) ->
 load_instance_from_file(File) ->
     emqx_resource_instance:load_file(File).
 
--spec load_instance_from_config(binary() | map()) -> ok.
+-spec load_instance_from_config(binary() | map()) -> {ok, resource_data()} | {error, term()}.
 load_instance_from_config(Config) ->
     emqx_resource_instance:load_config(Config).
 

apps/emqx_resource/src/emqx_resource_transform.erl

@@ -29,7 +29,7 @@ parse_transform(Forms, _Opts) ->
 
 debug_print(Mod, Ts) ->
     {ok, Io} = file:open("./" ++ atom_to_list(Mod) ++ ".trans.erl", [write]),
-    do_debug_print(Io, Ts),
+    _ = do_debug_print(Io, Ts),
     file:close(Io).
 
 do_debug_print(Io, Ts) when is_list(Ts) ->