run golangci-lint and apply suggested fixes

rpc/dataconn/timeoutconn/internal/wireevaluator/wireevaluator_closewrite.go

@@ -52,9 +52,6 @@ func (CloseWrite) sender(wire transport.Wire) {
 		log.Printf("closeErr=%T %s", closeErr, closeErr)
 	}()
 
-	type opResult struct {
-		err error
-	}
 	writeDone := make(chan struct{}, 1)
 	go func() {
 		close(writeDone)

rpc/dataconn/timeoutconn/timeoutconn.go

@@ -95,7 +95,7 @@ restart:
 		return n, err
 	}
 	var nCurRead int
-	nCurRead, err = c.Wire.Read(p[n:len(p)])
+	nCurRead, err = c.Wire.Read(p[n:])
 	n += nCurRead
 	if netErr, ok := err.(net.Error); ok && netErr.Timeout() && nCurRead > 0 {
 		err = nil
@@ -111,7 +111,7 @@ restart:
 		return n, err
 	}
 	var nCurWrite int
-	nCurWrite, err = c.Wire.Write(p[n:len(p)])
+	nCurWrite, err = c.Wire.Write(p[n:])
 	n += nCurWrite
 	if netErr, ok := err.(net.Error); ok && netErr.Timeout() && nCurWrite > 0 {
 		err = nil

rpc/dataconn/timeoutconn/timeoutconn_test.go

@@ -102,7 +102,7 @@ func TestNoPartialReadsDueToDeadline(t *testing.T) {
 		// io.Copy will encounter a partial read, then wait ~50ms until the other 5 bytes are written
 		// It is still going to fail with deadline err because it expects EOF
 		n, err := io.Copy(&buf, bc)
-		readDuration := time.Now().Sub(beginRead)
+		readDuration := time.Since(beginRead)
 		t.Logf("read duration=%s", readDuration)
 		t.Logf("recv done n=%v err=%v", n, err)
 		t.Logf("buf=%v", buf.Bytes())
@@ -153,7 +153,7 @@ func TestPartialWriteMockConn(t *testing.T) {
 	buf := []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 	begin := time.Now()
 	n, err := mc.Write(buf[:])
-	duration := time.Now().Sub(begin)
+	duration := time.Since(begin)
 	assert.NoError(t, err)
 	assert.Equal(t, 5, n)
 	assert.True(t, duration > 100*time.Millisecond)