serial: sh-sci: Make probe fail for ports that exceed the maximum count

The driver supports a maximum number of ports configurable at compile
time. Make sure the probe() method fails when registering a port that
exceeds the maximum instead of returning success without registering the
port.

This fixes a crash at system suspend time, when the driver tried to
suspend a non-registered port using the UART core.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sh-sci.c

@@ -2391,7 +2391,7 @@ static int __devinit sci_probe_single(struct platform_device *dev,
 			   index+1, SCI_NPORTS);
 		dev_notice(&dev->dev, "Consider bumping "
 			   "CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
-		return 0;
+		return -EINVAL;
 	}
 
 	ret = sci_init_single(dev, sciport, index, p);