media: staging/imx: Missing assignment in imx_media_capture_device_register()

There was supposed to be a "ret = " assignment here, otherwise the
error handling on the next line won't work.

Fixes: 64b5a49d ("[media] media: imx: Add Capture Device Interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/imx/imx-media-capture.c

@@ -778,7 +778,7 @@ int imx_media_capture_device_register(struct imx_media_video_dev *vdev)
 	/* setup default format */
 	fmt_src.pad = priv->src_sd_pad;
 	fmt_src.which = V4L2_SUBDEV_FORMAT_ACTIVE;
-	v4l2_subdev_call(sd, pad, get_fmt, NULL, &fmt_src);
+	ret = v4l2_subdev_call(sd, pad, get_fmt, NULL, &fmt_src);
 	if (ret) {
 		v4l2_err(sd, "failed to get src_sd format\n");
 		goto unreg;