UBUNTU-CVE-2026-98820: Low severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: blk-mq: set RQFUSESCHED when the operation is known The cached requests are allocated for one operation but can be handed out for another. A passthrough command has RQFUSESCHED cleared, so using those flags for a subsequent read/write bio will insert it into the scheduler without ->preparerequest() and frees it without ->finishrequest(). For kyber, this leaks the domain token acquired at dispatch and stalls the queue. Don't set RQFUSESCHED based on the first operation the batch happened to be allocated for. Instead, set it after the request is claimed by an operation. Introduce a helper function, blkmqrqlateinit() for this, and absorb blkmqrqtimeinit() since the two run together.