usb: device_next: allow terminating descriptor set with NULL

Do not require nil descriptor at the end of descriptor set because it
serves no other purpose than a sentinel. Just end processing on first
NULL pointer within descriptor set.

Signed-off-by: Tomasz Moń <tomasz.mon@nordicsemi.no>
Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>
4 files changed