staging: comedi: remove 'bi.subdevice < 0' check in do_bufinfo_ioctl()

Type of variable 'bi' is struct comedi_bufinfo and 'subdevice' is
defined as unsigned, so there is no need to check if it is less then
zero.

Signed-off-by: Güngör Erseymen <gelurine@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/comedi_fops.c

@@ -913,7 +913,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev,
 	if (copy_from_user(&bi, arg, sizeof(bi)))
 		return -EFAULT;
 
-	if (bi.subdevice >= dev->n_subdevices || bi.subdevice < 0)
+	if (bi.subdevice >= dev->n_subdevices)
 		return -EINVAL;
 
 	s = &dev->subdevices[bi.subdevice];