Windows: WinUSB: Allow caching config descriptors to fail

Windows: WinUSB: Allow caching config descriptors to fail

Certain buggy devices may not provide all the advertised configuration
descriptors. Prior to this commit, failure to cache any one of the
descriptors would result in all of the descriptors being freed and the
device being inaccessible. Work around this by continuing on if fetching
a configuration descriptor fails. The device may still be usable if the
descriptor for the current configuration was successfully retrieved.

Closes #390

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>