Release resources when exiting on error.

Fixes: 1a5c0b28 ("ASoC: stm32: spdifrx: manage identification registers")
Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Link: https://lore.kernel.org/r/20200318144125.9163-2-olivier.moysan@st.comSigned-off-by: Mark Brown <broonie@kernel.org>