net: phy: marvell10g: fix return value on error

stable inclusion
from stable-v5.10.114
commit 1204386e2657b5aa942d21aff353a84bea84f5b7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5IY1V

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1204386e2657b5aa942d21aff353a84bea84f5b7



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[ Upstream commit 0ed9704b ]

Return back the error value that we get from phy_read_mmd().

Fixes: c84786fa ("net: phy: marvell10g: read copper results from CSSR1")
Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/f47cb031aeae873bb008ba35001607304a171a20.1650868058.git.baruch@tkos.co.il


Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>