ASoC: pcm: Fix the compat pointer assignment

Compat ioctl pointer is assigned to ioctl field instead of compat_ioctl
member variable. Change updates the assignment.

CRs-fixed: 688027
Change-Id: I248e3225493f0ceafcb5e70ce0ff827ab77c7a74
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>