kernel: arm64/sve: Discard stale CPU state when handling SVE traps

In the Linux kernel, the following vulnerability has been resolved: arm64/sve: Discard stale CPU state when handling SVE traps The logic for handling SVE traps manipulates saved FPSIMD/SVE state incorrectly, and a race with preemption can result in a task having TIFSVE set and TIFFOREIGNFPSTATE...