usb: Remove #undef ERROR
usb: Remove #undef ERROR

Our "debug.h" header does not define ERROR anymore, so there is no
conflict with an existing ERROR macro.

Signed-off-by: Paul Cercueil <a027184a55211cd23e3f3094f1fdc728df5e0500@crapouillou.net>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio