CVE-2026-72016 cpu/hotplug: Fix NULL kobject warning in cpuhp_smt_enable()

In the Linux kernel, the following vulnerability has been resolved: cpu/hotplug: Fix NULL kobject warning in cpuhpsmtenable On arm64, when booting with maxcpus greater than the number of present CPUs e.g., QEMU -smp cpus=4,maxcpus=8, some CPUs are marked as 'present' but have not yet been...