atl1e: checking the status of atl1e_write_phy_reg

[ Upstream commit ff07d48d7bc0974d4f96a85a4df14564fb09f1ef ]

atl1e_write_phy_reg() could fail. The fix issues an error message when
it fails.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>