can: sja1000: remove redundant variable ret

Return value directly from register_candev() instead of
getting value from redundant variable ret.
Reported-by: NZeal Robot <zealci@zte.com.cn>
Signed-off-by: NJinpeng Cui <cui.jinpeng2@zte.com.cn>
Link: https://lore.kernel.org/all/20220831161835.306079-1-cui.jinpeng2@zte.com.cnSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/sja1000/sja1000.c

@@ -661,8 +661,6 @@ static const struct ethtool_ops sja1000_ethtool_ops = {
 
 int register_sja1000dev(struct net_device *dev)
 {
-	int ret;
-
 	if (!sja1000_probe_chip(dev))
 		return -ENODEV;
 
@@ -673,9 +671,7 @@ int register_sja1000dev(struct net_device *dev)
 	set_reset_mode(dev);
 	chipset_init(dev);
 
-	ret =  register_candev(dev);
-
-	return ret;
+	return register_candev(dev);
 }
 EXPORT_SYMBOL_GPL(register_sja1000dev);