speakup: Simplify spk_ttyio_out error handling.

This avoids most code indentation

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20210126222147.3848175-4-samuel.thibault@ens-lyon.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>