[media] s5p-jpeg: Eliminate double kfree()

video_unregister_device() calls device_unregister(), which calls
put_device(), which calls kobject_put(), and if this is the last reference
then kobject_release() is called, which calls kobject_cleanup(), which
calls ktype's release method which happens to be device_release() in this
case, which calls dev->release(), which happens to be
v4l2_device_release() in this case, which calls vdev->release(), which
happens to be video_device_release(). But video_device_release() is
called explicitly both in error recovery path of s5p_jpeg_probe() and
in s5p_jpeg_remove(). The pointers in question are not nullified between
the two calls, so this is harmful.

This patch fixes the driver so that video_device_release() is not called
twice for the same object.

Signed-off-by: Andrzej Pietrasiewicz <[e-mail]>
Signed-off-by: Sylwester Nawrocki <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/s5p-jpeg/jpeg-core.c

···
 	ret = video_register_device(jpeg->vfd_encoder, VFL_TYPE_GRABBER, -1);
 	if (ret) {
 		v4l2_err(&jpeg->v4l2_dev, "Failed to register video device\n");
-		goto enc_vdev_alloc_rollback;
+		video_device_release(jpeg->vfd_encoder);
+		goto vb2_allocator_rollback;
 	}
 
 	video_set_drvdata(jpeg->vfd_encoder, jpeg);
···
 	ret = video_register_device(jpeg->vfd_decoder, VFL_TYPE_GRABBER, -1);
 	if (ret) {
 		v4l2_err(&jpeg->v4l2_dev, "Failed to register video device\n");
-		goto dec_vdev_alloc_rollback;
+		video_device_release(jpeg->vfd_decoder);
+		goto enc_vdev_register_rollback;
 	}
 
 	video_set_drvdata(jpeg->vfd_decoder, jpeg);
···
 
 	return 0;
 
-dec_vdev_alloc_rollback:
-	video_device_release(jpeg->vfd_decoder);
-
 enc_vdev_register_rollback:
 	video_unregister_device(jpeg->vfd_encoder);
-
-enc_vdev_alloc_rollback:
-	video_device_release(jpeg->vfd_encoder);
 
 vb2_allocator_rollback:
 	vb2_dma_contig_cleanup_ctx(jpeg->alloc_ctx);
···
 	pm_runtime_disable(jpeg->dev);
 
 	video_unregister_device(jpeg->vfd_decoder);
-	video_device_release(jpeg->vfd_decoder);
 	video_unregister_device(jpeg->vfd_encoder);
-	video_device_release(jpeg->vfd_encoder);
 	vb2_dma_contig_cleanup_ctx(jpeg->alloc_ctx);
 	v4l2_m2m_release(jpeg->m2m_dev);
 	v4l2_device_unregister(&jpeg->v4l2_dev);