ASoC: sn95031: sst_platform: intel_sst: fix errors reported by klocwork

ASoC: sn95031: sst_platform: intel_sst: fix errors reported by klocwork

Variables in audio driver code need to be freed properly to avoid possible memory leaks.
Also the unchecked return of variables from called functions may cause out of bound errors
like in case of array indexes.

This patch fixes these errors (as pointed by the klocwork )in sst driver and ASoC code by
freeing the memory of unused variables and checking on the returned value by called function
to array index to avoid posible array out of bound runtime error.

Change-Id: I1710889976e0d257ba2e7bede338cc2f056ae095
Signed-off-by: Abhay <abhay.joshi@intel.com>