If the snd_sof_dsp_send_msg() failed then we have already returned from
sof_ipc_tx_message_unlocked() with the error message.

There is no need to check if ret is really 0 after this and we can return
directly the return value from tx_wait_done()

At the same time make the remaining checks for error (ret) to match.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210916125725.25934-1-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>