fix go-cni race condition

Signed-off-by: Michael Zappa <michael.zappa@gmail.com>

vendor/github.com/petermattis/goid/goid_slow.go

@@ -0,0 +1,24 @@
+// Copyright 2016 Peter Mattis.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License. See the AUTHORS file
+// for names of contributors.
+
+//go:build (go1.4 && !go1.5 && !amd64 && !amd64p32 && !arm && !386) || (go1.5 && !386 && !amd64 && !amd64p32 && !arm && !arm64 && !s390x)
+// +build go1.4,!go1.5,!amd64,!amd64p32,!arm,!386 go1.5,!386,!amd64,!amd64p32,!arm,!arm64,!s390x
+
+package goid
+
+// Get returns the id of the current goroutine.
+func Get() int64 {
+	return getSlow()
+}