[media] cx88: uninitialized variable

Fixes a gcc warning:

drivers/media/video/cx88/cx88-video.c:772:
	warning: ‘core’ may be used uninitialized in this function
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx88/cx88-video.c

@@ -752,7 +752,7 @@ static int video_open(struct file *file)
 {
 	struct video_device *vdev = video_devdata(file);
 	struct cx8800_dev *dev = video_drvdata(file);
-	struct cx88_core *core;
+	struct cx88_core *core = dev->core;
 	struct cx8800_fh *fh;
 	enum v4l2_buf_type type = 0;
 	int radio = 0;
@@ -786,7 +786,6 @@ static int video_open(struct file *file)
 	fh->fmt      = format_by_fourcc(V4L2_PIX_FMT_BGR24);
 
 	mutex_lock(&core->lock);
-	core = dev->core;
 
 	videobuf_queue_sg_init(&fh->vidq, &cx8800_video_qops,
 			    &dev->pci->dev, &dev->slock,