[REBASED on main (r3branch)from r2-stable branch] audio: sst: Fix for errors revealed...

[REBASED on main (r3branch)from r2-stable branch] audio: sst: Fix for errors revealed by klocwork

BZ: 17975

Fixes errors in driver revealed by klocwork and other static analysis tools

Change-Id: I661df04fd1fae138a6c21842ff5699bc28d046bf
old-Change-Id: Iea1f15842e6c7f39a90a7c038e4d9817131f29a6
Signed-off-by: Omair Mohammed Abdullah <omair.m.abdullah@intel.com>
Reviewed-on: http://android.intel.com:8080/29537
Reviewed-by: M, Arulselvan <arulselvan.m@intel.com>
Tested-by: M, Arulselvan <arulselvan.m@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>