msm: sensor: Add mutex lock during ois power down operations

Protecting operations performed during ois powerdown
from race condition by adding mutex locks.

CRs-Fixed: 2081806
Change-Id: I8a918dc306e639d50a896c8d77f8eb7a72fcb195
Signed-off-by: Rahul Sharma <sharah@codeaurora.org>

drivers/media/platform/msm/ais/sensor/ois/msm_ois.c

@@ -623,11 +623,13 @@ static long msm_ois_subdev_ioctl(struct v4l2_subdev *sd,
 			pr_err("o_ctrl->i2c_client.i2c_func_tbl NULL\n");
 			return -EINVAL;
 		}
+		mutex_lock(o_ctrl->ois_mutex);
 		rc = msm_ois_power_down(o_ctrl);
 		if (rc < 0) {
 			pr_err("%s:%d OIS Power down failed\n",
 				__func__, __LINE__);
 		}
+		mutex_unlock(o_ctrl->ois_mutex);
 		return msm_ois_close(sd, NULL);
 	default:
 		return -ENOIOCTLCMD;