staging: comedi: adv_pci1760: Do not return EINVAL for CMDF_ROUND_DOWN.

The CMDF_ROUND_DOWN case falls through and so always returns -EINVAL.

Fixes: 14b93bb6 ("staging: comedi: adv_pci_dio: separate out PCI-1760 support")
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/adv_pci1760.c

@@ -196,6 +196,7 @@ static int pci1760_pwm_ns_to_div(unsigned int flags, unsigned int ns)
 		break;
 	case CMDF_ROUND_DOWN:
 		divisor = ns / PCI1760_PWM_TIMEBASE;
+		break;
 	default:
 		return -EINVAL;
 	}