lwip: Remove errno definitions.
lwip: Remove errno definitions.

johnkingsley/aprinter,johnkingsley/aprinter,ambrop72/aprinter,ambrop72/aprinter,ambrop72/aprinter,ambrop72/aprinter,ambrop72/aprinter,ambrop72/aprinter,johnkingsley/aprinter,johnkingsley/aprinter,ambrop72/aprinter,johnkingsley/aprinter,johnkingsley/aprinter,johnkingsley/aprinter