fixed_phy_register() returns -EPROBE_DEFER, -EINVAL and -EBUSY,
etc, in addition to -ENODEV. The Best practice is to return these
error codes with PTR_ERR().
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Acked-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>