I've finally noticed that mdiobus_scan() also returns either NULL or error
value on failure.  Return ERR_PTR(-ENODEV) instead of NULL since this is
the  error value  already filtered out by the callers that want to ignore
the  MDIO address scan failure...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>