net: marvell: prestera: Fix error return code in prestera_port_create()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 501ef306 ("net: marvell: prestera: Add driver for Prestera family ASIC devices")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1607071782-34006-1-git-send-email-zhangchangzhong@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/prestera/prestera_main.c

@@ -318,8 +318,10 @@ static int prestera_port_create(struct prestera_switch *sw, u32 id)
 		goto err_port_init;
 	}
 
-	if (port->fp_id >= PRESTERA_MAC_ADDR_NUM_MAX)
+	if (port->fp_id >= PRESTERA_MAC_ADDR_NUM_MAX) {
+		err = -EINVAL;
 		goto err_port_init;
+	}
 
 	/* firmware requires that port's MAC address consist of the first
 	 * 5 bytes of the base MAC address