A request to set alternate zero for a non-existent interface
would succeed because of the inappropriate order of checks.
Move the check if the desired alternate is the same as the
current one after the check if interface exists.
Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>
The device supprt brings support for multiple stack instances,
multiple configuration, asynchronous transfer model, ability to
change most of the properties of a device at runtime and
the composition of configuration and classes at runtime.
The stack requires new UDC driver API and is not compatible
with old driver API (usb_dc_). The classes (functions) of old
(current) USB device stack cannot be used with new ones and must
be ported.
Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>