[mpeg2] select patch for kfir.c

[Bram Stolk <b.stolk@chello.nl>]

Hello,

The kfir device currently does not support select() calls,
so I fixed this.

Here is an improved implementation of the poll func in kfir.c, which
will provide a working select() mechanism.

   Bram

static unsigned int kfir_poll
(
  struct video_device *dev,
  struct file *file,
  poll_table *wait
) 
{
  struct kfir_dev *kfir=(struct kfir_dev *) dev;

  if (kfir->readp == kfir->writep)
  {
    // no data
    return 0;
  }
  else
  {
    // data
    return (POLLIN | POLLRDNORM);
  }
}