run varcheck in gometalinter

.gometalinter.json

@@ -8,6 +8,7 @@
   "Enable": [
     "deadcode",
     "ineffassign",
+    "varcheck",
     "vet"
   ],
   "Linters": {

integrationtests/chrome/chrome_suite_test.go

@@ -27,8 +27,6 @@ import (
 )
 
 const (
-	nChromeRetries = 8
-
 	dataLen     = 500 * 1024       // 500 KB
 	dataLongLen = 50 * 1024 * 1024 // 50 MB
 )

packet_packer_test.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/golang/mock/gomock"
 	"github.com/lucas-clemente/quic-go/internal/ackhandler"
-	"github.com/lucas-clemente/quic-go/internal/flowcontrol"
 	"github.com/lucas-clemente/quic-go/internal/handshake"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/wire"
@@ -57,7 +56,6 @@ var _ = Describe("Packet packer", func() {
 		packer           *packetPacker
 		publicHeaderLen  protocol.ByteCount
 		maxFrameSize     protocol.ByteCount
-		cryptoStream     cryptoStreamI
 		mockStreamFramer *MockStreamFrameSource
 	)
 
@@ -65,7 +63,6 @@ var _ = Describe("Packet packer", func() {
 		version := versionGQUICFrames
 		mockSender := NewMockStreamSender(mockCtrl)
 		mockSender.EXPECT().onHasStreamData(gomock.Any()).AnyTimes()
-		cryptoStream = newCryptoStream(mockSender, flowcontrol.NewStreamFlowController(version.CryptoStreamID(), false, flowcontrol.NewConnectionFlowController(1000, 1000, nil), 1000, 1000, 1000, nil), version)
 		mockStreamFramer = NewMockStreamFrameSource(mockCtrl)
 
 		packer = newPacketPacker(