NonSFI sandbox: restrict futex(2) operations.

sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc

Index: sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
diff --git a/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc b/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
index 145df9b94fcc5cb5ef7a8edcc9a1cbe85c40e268..4ccacdb30ef3351e3a59e899a0e5db1c3f38302f 100644
--- a/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
+++ b/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
@@ -229,12 +229,10 @@ ResultExpr RestrictKillTarget(pid_t target_pid, int sysno) {
 ResultExpr RestrictFutex() {
   const int kAllowedFutexFlags = FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME;
   const int kOperationMask = ~kAllowedFutexFlags;
-
   const Arg<int> op(1);
   return Switch(op & kOperationMask)
       .CASES((FUTEX_WAIT,
               FUTEX_WAKE,
-              FUTEX_FD,
               FUTEX_REQUEUE,
               FUTEX_CMP_REQUEUE,
               FUTEX_WAKE_OP,