msm: vidc: Fix race condition between s_fmt & query_ctrl

- In s_fmt, there might be a codec change and here we are
  free the ctrl handler, at the same time client may call
  query ctrl and this will lead to null pointer access.
- To resolve null pointer access, do not free ctrl handler
  and add new codec controls to the same ctrl handler.

Change-Id: Iee87d5cb4d65e31d405cb1fc9f82bebab696d027
Signed-off-by: Vedang Nagar <quic_vnagar@quicinc.com>

driver/vidc/inc/msm_vidc_inst.h

@@ -87,7 +87,6 @@ struct msm_vidc_inst {
 	struct v4l2_fh                     event_handler;
 	struct v4l2_m2m_dev               *m2m_dev;
 	struct v4l2_m2m_ctx               *m2m_ctx;
-	struct v4l2_ctrl                 **ctrls;
 	u32                                num_ctrls;
 	enum hfi_rate_control              hfi_rc_type;
 	enum hfi_layer_encoding_type       hfi_layer_type;