asoc: Add null check for kctl private_data in volume controls

In platform driver volume controls, add null check
for kctl private data before access.

CRs-Fixed: 2611397
Change-Id: I49bdac2bb780a7116e54c20bf5f0d01f13a53165
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>
3 files changed