libusb io error on device reset

[grvvy]

Steps to reproduce

1. $ ubertooth-dfu -r

Expected behaviour

Device should reset, and it does, but it produces a potentially misleading io error. Possibly related to #300.

Version information

Operating system: Ubuntu 20.04.3

Ubertooth tools version (ubertooth-rx -V): libubertooth 1.1 (2020-12-R1), libbtbb 1.0 (2018-06-R1)
Built and installed libbtbb from 2020-12-R1 but version string was still set to 2018-06-R1:

/libbtbb-2020-12-R1/build$ cmake ..
-- The C compiler identification is GNU 9.3.0
-- The CXX compiler identification is GNU 9.3.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Setting version string 2018-06-R1

Ubertooth firmware version (ubertooth-util -v): Firmware version: 2020-12-R1 (API:1.07)

Output

$ ubertooth-dfu -r
Switching to DFU mode...
libUSB Error: Input/Output Error:  (-1)