staging: comedi: ni_at_a2150: checkpatch.pl cleanup (missing blank line)

Fix the checkpatch.pl warning:

WARNING: Missing a blank line after declarations
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_at_a2150.c

@@ -690,6 +690,7 @@ static int a2150_set_chanlist(struct comedi_device *dev,
 static int a2150_probe(struct comedi_device *dev)
 {
 	int status = inw(dev->iobase + STATUS_REG);
+
 	return ID_BITS(status);
 }