We always want to know as much context as possible. Which exact
timeslot on which line of which interface ha logged something?
Change-Id: I3d8909b396928ed3c023b8ac47fa9ec72c99e681
libosmousb, recently introduced to libosmocore.git, is taking care
of main loop integration of libusb into osmo_select_main(). This
means we don't need to do any polling here anymore.
Change-Id: I3f3b61dfa217d6ef8c17970b2cf1cc627bb13bbe