Correct SerialUSB return value#143

Merged

agdl merged 2 commits intoarduino:masterfrom

sandeepmistry:cdc-write-return-value

Jun 6, 2016

Commits on May 27, 2016

Make return value of USBDeviceClass::send the bytes sent
sandeepmistry
committed
Change return value of Serial_::write to be the # of bytes written
sandeepmistry
committed