CVE-2024-57849 s390/cpum_sf: Handle CPU hotplug remove during sampling

In the Linux kernel, the following vulnerability has been resolved: s390/cpumsf: Handle CPU hotplug remove during sampling CPU hotplug remove handling triggers the following function call sequence: CPUHPAPPERFS390SFONLINE -- s390pmusfofflinecpu ... CPUHPAPPERFONLINE -- perfeventexitcpu The s390...