net: phy: at803x: fix error return code in at803x_probe()

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

Fixes: 3265f421

 ("net: phy: at803x: add fiber support")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20221118103635.254256-1-weiyongjun@huaweicloud.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>