msm: vidc: Free smem client after moving core to UNINIT

If userspace crashes prematurely, there will be a good chance that the
driver hasn't unmapped or freed certain buffers.  These buffers will be
freed in the state transition to UNINIT.  At that point the smem client
needs to be valid for the free/unmaps to be valid.

CRs-Fixed: 611946
Change-Id: I089dcbd1e79f1c2a8671e5719d3a5dbc9926b252
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>
msm: vidc: Query the core on VIDIOC_G_FMT