ASoC: Fix resource leak in goni_wm8994.c

Properly free allocated resources in goni_init() error path.
Add missing snd_soc_unregister_dai() in goni_exit().

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Jassi Brar <jassi.brar@samsung.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>