ASoC: wm_adsp: fix memleak in wm_adsp_buffer_populate

ASoC: wm_adsp: fix memleak in wm_adsp_buffer_populate

When wm_adsp_buffer_read() fails, we should free buf->regions.
Otherwise, the callers of wm_adsp_buffer_populate() will
directly free buf on failure, which makes buf->regions a leaked
memory.

Fixes: a792af69b08f ("ASoC: wm_adsp: Refactor compress stream initialisation")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20231204074158.12026-1-dinghao.liu@zju.edu.cn
Signed-off-by: Mark Brown <broonie@kernel.org>