watchdog: ts72xx_wdt: Propagate return value from timeout_to_regval

timeout_to_regval() returns a valid error code. Might as well use it.

Signed-off-by: Guenter Roeck <[e-mail]>
Signed-off-by: Wim Van Sebroeck <[e-mail]>

drivers/watchdog/ts72xx_wdt.c

···
 		dev_err(&wdt->pdev->dev,
 			"failed to convert timeout (%d) to register value\n",
 			timeout);
-		return -EINVAL;
+		return regval;
 	}
 
 	if (mutex_lock_interruptible(&wdt->lock))