Airspy R2 remains in RX mode/high power draw after SDRT exits

[cfc62]

I had noticed my R2s remaining warm to the touch even after quitting SDRT.

With a USB power meter, when initially plugged in w/o SDRT running, they draw quite low power - 0.04A at 5V. The only LED lit on the board is the power indicator.

Starting SDRTrunk increases the power draw to 0.25A, and the RX LED is lit.

However, when quitting SDRTrunk, the power draw remains at 0.25A and the RX LED remains lit. To get back to the low power usage state requires either a USB unplug/replug cycle or a manual reset, which requires the case to be removed.