CVE-2025-37878 perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix WARNON!ctx in freeevent for partial init Move the getctxchildctx call and the childevent-ctx assignment to occur immediately after the child event is allocated. Ensure that childevent-ctx is non-NULL before any...