net: phy: improve phy_read_poll_timeout

cond sometimes is (val & MASK) what may result in a false positive
if val is a negative errno. We shouldn't evaluate cond if val < 0.
This has no functional impact here, but it's not nice.
Therefore switch order of the checks.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/6d8274ac-4344-23b4-d9a3-cad4c39517d4@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>