ASoC: topology: KUnit: Followup prototype change of snd_soc_unregister_card()

ASoC: topology: KUnit: Followup prototype change of snd_soc_unregister_card()

snd_soc_unregister_card() was recently converted to return void. Only
the first instance was adapted, so convert the remaining ones now to fix
building the topology test.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 6964ff80926f ("ASoC: core: Make snd_soc_unregister_card() return void")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220622210629.286487-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>