of_get_phy_mode may fail and return a negative error code;
the fix checks the return value of of_get_phy_mode and
returns -EINVAL of it fails.
Signed-off-by: NKangjie Lu <kjlu@umn.edu>
Acked-by: NMaxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>