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 <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/ts72xx_wdt.c b/drivers/watchdog/ts72xx_wdt.c
index df5dd55..09d4831 100644
--- a/drivers/watchdog/ts72xx_wdt.c
+++ b/drivers/watchdog/ts72xx_wdt.c
@@ -192,7 +192,7 @@
 		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))