[media] V4L: soc_camera_platform: do not leave dangling invalid pointers

The life-time of soc-camera device objects can be longer, than the
time, it is attached to a client driver, therefore all references to
the driver own data have to be cleared, when the driver is detached.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/soc_camera_platform.c b/drivers/media/video/soc_camera_platform.c
index f5ebe59..c8f6b18 100644
--- a/drivers/media/video/soc_camera_platform.c
+++ b/drivers/media/video/soc_camera_platform.c
@@ -173,7 +173,9 @@
 static int soc_camera_platform_remove(struct platform_device *pdev)
 {
 	struct soc_camera_platform_priv *priv = get_priv(pdev);
+	struct soc_camera_platform_info *p = v4l2_get_subdevdata(&priv->subdev);
 
+	p->icd->control = NULL;
 	v4l2_device_unregister_subdev(&priv->subdev);
 	platform_set_drvdata(pdev, NULL);
 	kfree(priv);