Fixed coverity defects regarding pass-by-value

sandbox/linux/seccomp-bpf/sandbox_bpf.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <time.h>
 
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
 #include "sandbox/linux/seccomp-bpf/verifier.h"
 
 // The kernel gives us a sandbox, we turn it into a playground :-)
@@ skipping 231 matching lines @@
       sb.st_nlink != 3 ||
       HANDLE_EINTR(close(task))) {
     if (task >= 0) {
       if (HANDLE_EINTR(close(task))) { }
     }
     return false;
   }
   return true;
 }
 
-static bool isDenied(Sandbox::ErrorCode code) {
+static bool isDenied(const Sandbox::ErrorCode& code) {
   return (code & SECCOMP_RET_ACTION) == SECCOMP_RET_TRAP ||
          (code >= (SECCOMP_RET_ERRNO + 1) &&
           code <= (SECCOMP_RET_ERRNO + 4095));
 }
 
 void Sandbox::policySanityChecks(EvaluateSyscall syscallEvaluator,
                                  EvaluateArguments) {
   // Do some sanity checks on the policy. This will warn users if they do
   // things that are likely unsafe and unintended.
   // We also have similar checks later, when we actually compile the BPF
@@ skipping 423 matching lines @@
 bool Sandbox::dryRun_                   = false;
 Sandbox::SandboxStatus Sandbox::status_ = STATUS_UNKNOWN;
 int    Sandbox::proc_fd_                = -1;
 Sandbox::Evaluators Sandbox::evaluators_;
 Sandbox::Traps *Sandbox::traps_         = NULL;
 Sandbox::TrapIds Sandbox::trapIds_;
 Sandbox::ErrorCode *Sandbox::trapArray_ = NULL;
 size_t Sandbox::trapArraySize_          = 0;
 
 }  // namespace