This patch fixes a few problems with ub and cleans up a couple of things:
- Bump UB_MAX_REQ_SG, this allows to burn CDs
- Drop initialization of urb.transfer_flags,
now that URB_UNLINK_ASYNC is gone
- Add forgotten processing of stalls at GetMaxLUN
- Remove a few more P3-tagged printks whose time has come
- Correct comment about ZIP-100