korad-kaxxxxp: Add workaround for a Korad KA3005P issue.

korad-kaxxxxp: Add workaround for a Korad KA3005P issue.

In some situations, the reply to the *IDN? command contains an
additional trailing 0x01 byte for unknown reasons.

This issue seems to be reproducible by changing the voltage using the knobs
on the device, then turning on the output and turning it off again.

The next korad-kaxxxxp scan() operation would contain the trailing 0x01
byte, which would lead to the detection of the device in libsigrok no
longer working until the next power-cycle.

Work around this issue by treating both the ID string with and without
the trailing 0x01 byte as valid.