ASoC: pcm: free path list before exiting from error conditions

dpcm_path_get() allocates dynamic memory to hold path list.
Corresponding dpcm_path_put() must be called to free the memory.
dpcm_path_put() is not called under several error conditions.
This leads to memory leak.

Signed-off-by: Patrick Lai <plai@codeaurora.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org