lib: json: fix arr_encode()

The JSON library doesn't properly encode arrays whose elements are of
object type. Fix that.

This fix avoids allocating a temporary descriptor on the stack, and
keeps the size of struct json_obj_descr unchanged, by preserving an
unintuitive size optimization made by the library.  See the comments
in the patch for more details.

Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
1 file changed