[media] vb2: fix wrong owner check

Check against q->fileio to see if the queue owner should be set or not.
The former check against the return value of read or write is wrong, since
read/write can return an error, even if the queue is in streaming mode.
For example, EAGAIN when in non-blocking mode.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/v4l2-core/videobuf2-core.c

@@ -2278,7 +2278,7 @@ ssize_t vb2_fop_write(struct file *file, char __user *buf,
 		goto exit;
 	err = vb2_write(vdev->queue, buf, count, ppos,
 		       file->f_flags & O_NONBLOCK);
-	if (err >= 0)
+	if (vdev->queue->fileio)
 		vdev->queue->owner = file->private_data;
 exit:
 	if (lock)
@@ -2300,7 +2300,7 @@ ssize_t vb2_fop_read(struct file *file, char __user *buf,
 		goto exit;
 	err = vb2_read(vdev->queue, buf, count, ppos,
 		       file->f_flags & O_NONBLOCK);
-	if (err >= 0)
+	if (vdev->queue->fileio)
 		vdev->queue->owner = file->private_data;
 exit:
 	if (lock)