[USBSTOR] CORE-19773 Clamp LUN - Don't just assert on a POSSIBLE case

[anonymou0719]

This PR ports a small fix from DarkFire01/reactos into ReactOS-Longhorn-Initiative/reactos.

We’re a team doing OSS research, and part of what we do is track useful fixes and help move them across forks so the different trees stay aligned and don’t drift too far apart.

Ported commit: http://github.com/DarkFire01/reactos/commit/2d79555179c3ade2f5e6ee6650fb68b69e29a7cd

What changed (kept intentionally small and easy to review):

• Only one file is updated: drivers/usb/usbstor/scsi.c
• No refactors, cleanup, or formatting-only changes mixed in

Why this is useful:

• Fixes an issue in the USB storage (usbstor) SCSI handling code
• Helps keep the Longhorn Initiative fork consistent with fixes already available in DarkFire01/reactos

Testing:

• Local testing: not included yet (feel free to replace this line with the exact build/test commands you ran)
• CI link: N/A

If you’d prefer this rebased, squashed, or applied to a different branch, I’m happy to adjust.