CVE-2026-72068 posix-cpu-timers: Use u64 multiplication in update_rlimit_cpu()

In the Linux kernel, the following vulnerability has been resolved: posix-cpu-timers: Use u64 multiplication in updaterlimitcpu updaterlimitcpu converts the RLIMITCPU value to nanoseconds with u64 nsecs = rlimnew NSECPERSEC; On 32-bit kernels both rlimnew unsigned long and NSECPERSEC 1000000000L...