golint and go vet fixes
diff --git a/request-server_test.go b/request-server_test.go
index 4902349..5270fad 100644
--- a/request-server_test.go
+++ b/request-server_test.go
@@ -29,7 +29,7 @@
 	return cs.svr.Handlers.FileGet.(*root)
 }
 
-var sock string = "/tmp/rstest.sock"
+const sock = "/tmp/rstest.sock"
 
 func clientRequestServerPair(t *testing.T) *csPair {
 	ready := make(chan bool)
diff --git a/request.go b/request.go
index 8ef34fd..fb54508 100644
--- a/request.go
+++ b/request.go
@@ -20,11 +20,10 @@
 	Attrs    []byte // convert to sub-struct
 	Target   string // for renames and sym-links
 	// packet data
-	pkt_id      uint32
-	packetsLock sync.Mutex
-	packets     chan packet_data
+	pkt_id  uint32
+	packets chan packet_data
 	// reader/writer/readdir from handlers
-	stateLock sync.RWMutex
+	stateLock *sync.RWMutex
 	state     *state
 }
 
@@ -53,6 +52,7 @@
 	request := Request{Filepath: filepath.Clean(path)}
 	request.packets = make(chan packet_data, sftpServerWorkerCount)
 	request.state = &state{}
+	request.stateLock = &sync.RWMutex{}
 	return request
 }
 
diff --git a/request_test.go b/request_test.go
index b89b5a4..e537fc1 100644
--- a/request_test.go
+++ b/request_test.go
@@ -1,6 +1,8 @@
 package sftp
 
 import (
+	"sync"
+
 	"github.com/stretchr/testify/assert"
 
 	"bytes"
@@ -55,16 +57,17 @@
 // make sure len(fakefile) == len(filecontents)
 type fakefile [10]byte
 
-var filecontents []byte = []byte("file-data.")
+var filecontents = []byte("file-data.")
 
 func testRequest(method string) Request {
 	request := Request{
-		Filepath: "./request_test.go",
-		Method:   method,
-		Attrs:    []byte("foo"),
-		Target:   "foo",
-		packets:  make(chan packet_data, sftpServerWorkerCount),
-		state:    &state{},
+		Filepath:  "./request_test.go",
+		Method:    method,
+		Attrs:     []byte("foo"),
+		Target:    "foo",
+		packets:   make(chan packet_data, sftpServerWorkerCount),
+		state:     &state{},
+		stateLock: &sync.RWMutex{},
 	}
 	for _, p := range []packet_data{
 		packet_data{id: 1, data: filecontents[:5], length: 5},
@@ -162,7 +165,8 @@
 	request := testRequest("Stat")
 	pkt, err := request.handle(handlers)
 	assert.Nil(t, err)
-	spkt := pkt.(*sshFxpStatResponse)
+	spkt, ok := pkt.(*sshFxpStatResponse)
+	assert.True(t, ok)
 	assert.Equal(t, spkt.info.Name(), "request_test.go")
 }