Update to new release of moby/ipvs

hack/pin-dependency.sh github.com/moby/ipvs v1.1.0

- go to a fixed tag for `vishvananda/netns`
- no more references to `pkg/errors`

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

vendor/github.com/sirupsen/logrus/buffer_pool.go

@@ -26,15 +26,6 @@ func (p *defaultPool) Get() *bytes.Buffer {
 	return p.pool.Get().(*bytes.Buffer)
 }
 
-func getBuffer() *bytes.Buffer {
-	return bufferPool.Get()
-}
-
-func putBuffer(buf *bytes.Buffer) {
-	buf.Reset()
-	bufferPool.Put(buf)
-}
-
 // SetBufferPool allows to replace the default logrus buffer pool
 // to better meets the specific needs of an application.
 func SetBufferPool(bp BufferPool) {