cx82310_eth: fix error return code in cx82310_bind()

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

Fixes: ca139d7 ("cx82310_eth: re-enable ethernet mode after router reboot")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1605247627-15385-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Zhang Changzhong

drivers/net/usb/cx82310_eth.c

@@ -197,7 +197,8 @@ static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
 	}
 
 	/* enable ethernet mode (?) */
-	if (cx82310_enable_ethernet(dev))
+	ret = cx82310_enable_ethernet(dev);
+	if (ret)
 		goto err;
 
 	/* get the MAC address */