soundwire: stream: fix memory leak in stream config error path

soundwire: stream: fix memory leak in stream config error path

When stream config is failed, master runtime will release all
slave runtime in the slave_rt_list, but slave runtime is not
added to the list at this time. This patch frees slave runtime
in the config error path to fix the memory leak.

Fixes: 89e590535f32 ("soundwire: Add support for SoundWire stream management")
Signed-off-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Keyon Jie <yang.jie@intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210331004610.12242-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>