ASoC: Baytrail: fix error handling in sst_byt_dsp_init()

Calling "kfree(byt)" is a double free because that was allocated with
devm_kzalloc().  There were a couple places which leak "byt->msg".  That
memory is allocated in msg_empty_list_init().

Fixes: f7d01fd6 ('ASoC: Intel: Add Intel Baytrail SST DSP IPC support')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>