ASoC: msm: Add check for NULL pointer and buffer overflow

Changes to add check for NULL pointer before they
get dereferenced and check for buffer overflows
to ensure out of bound indexes of arrays are not
accessed.

Signed-off-by: Aravind Kumar <akumark@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>