fix: print error for msc buffer overflow that should never happen

In this situation the host is sending a new packet of data before the
last buffer has been handled. This should never happen and indicates a
breakdown in the NAK-sending behavior of the greater USB stack for an
MCU. When the buffer is full the USB stack should not ACK the final
packet and should NAK any new packets until the buffer is handled. If an
ACK is sent prematurely and NAKs are not sent in reply to overflow
packets this message will occur and the protocol will de-sync.

Author: mikesmitty

src/machine/usb/msc/scsi.go

@@ -245,6 +245,7 @@ func (m *msc) scsiCmdUnmap(cmd scsi.Cmd) {
 func (m *msc) scsiQueueTask(cmdType scsi.CmdType, b []byte) bool {
 	// Check if the incoming data is larger than our buffer
 	if int(m.queuedBytes)+len(b) > cap(m.buf) {
+		println("scsiQueueTask: OVERFLOW! queued:", m.queuedBytes, "len(b):", len(b), "cap:", cap(m.buf))
 		m.sendScsiError(csw.StatusFailed, scsi.SenseIllegalRequest, scsi.SenseCodeInvalidFieldInCDB)
 		return true
 	}