ASoC: soc-dai: tidyup return value of snd_soc_xlate_tdm_slot_mask()

commit 7f1186a8d738661 ("ASoC: soc-dai: check return value at
snd_soc_dai_set_tdm_slot()") checks return value of
xlate_tdm_slot_mask() (A1)(A2).

/*
* ...
(Y) * TDM mode can be disabled by passing 0 for @slots. In this case @tx_mask,
* @rx_mask and @slot_width will be ignored.
* ...
*/
int snd_soc_dai_set_tdm_slot(...)
{
...
if (...)
(A1) ret = dai->driver->ops->xlate_tdm_slot_mask(...);
else
(A2) ret = snd_soc_xlate_tdm_slot_mask(...);
if (ret)
goto err;
...
}

snd_soc_xlate_tdm_slot_mask() (A2) will return -EINVAL if slots was 0 (X),
but snd_soc_dai_set_tdm_slot() allow to use it (Y).

(A) static int snd_soc_xlate_tdm_slot_mask(...)
{
...
if (!slots)
(X) return -EINVAL;
...
}

Call xlate_tdm_slot_mask() only if slots was non zero.

Reported-by: Giedrius Trainavičius <giedrius@blokas.io>
Closes: https://lore.kernel.org/r/CAMONXLtSL7iKyvH6w=CzPTxQdBECf++hn8RKL6Y4=M_ou2YHow@mail.gmail.com
Fixes: 7f1186a8d738661 ("ASoC: soc-dai: check return value at snd_soc_dai_set_tdm_slot()")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/8734cdfx59.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>