CVE-2026-31733 sched_ext: Fix stale direct dispatch state in ddsp_dsq_id

In the Linux kernel, the following vulnerability has been resolved: schedext: Fix stale direct dispatch state in ddspdsqid @p-scx.ddspdsqid can be left set non-SCXDSQINVALID triggering a spurious warning in markdirectdispatch when the next wakeup's ops.selectcpu calls scxbpfdsqinsert, such as:...