ASoC: soc-ops: makes snd_soc_read_signed() void

snd_soc_read_signed() never return error. Let's makes it void.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/87tt8zyk6x.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>