Make golint fail on errors. (#105)

* make lint fail on errors
* fix lint errors

.github/workflows/build-and-test.yaml

@@ -11,7 +11,7 @@ jobs:
       - run: sudo apt-get install libusb-1.0-0-dev
       - run: go install golang.org/x/tools/cmd/cover@latest
       - run: go install golang.org/x/lint/golint@latest
-      - run: $HOME/go/bin/golint ./...
+      - run: $HOME/go/bin/golint -set_exit_status ./...
       - run: sh ./.github/test-coverage.sh
       - uses: shogo82148/actions-goveralls@v1
         with:

libusb.go

@@ -209,7 +209,7 @@ func (libusbImpl) getDevices(ctx *libusbContext) ([]*libusbDevice, error) {
 	for _, d := range devs {
 		ret = append(ret, (*libusbDevice)(d))
 	}
-	// devices must be dereferenced by the caller to prevent memoryleaks
+	// devices must be dereferenced by the caller to prevent memory leaks.
 	C.libusb_free_device_list(list, 0)
 	return ret, nil
 }

transfer_stream.go

@@ -269,14 +269,15 @@ func (w *WriteStream) Close() error {
 	return w.CloseContext(context.Background())
 }
 
-// Close signals end of data to write. Close blocks until all transfers
-// that were sent are finished. The error returned by Close is the first
-// error encountered during writing the entire stream (if any).
-// Close returning nil indicates all transfers completed successfully.
-// After Close, the total number of bytes successfully written can be
+// CloseContext signals end of data to write. CloseContext blocks until all
+// transfers that were sent are finished or until the context is canceled. The
+// error returned by CloseContext is the first error encountered during writing
+// the entire stream (if any).
+// CloseContext returning nil indicates all transfers completed successfully.
+// After CloseContext, the total number of bytes successfully written can be
 // retrieved using Written().
-// Close may not be called concurrently with Write, Close or Written.
-// CloseContext
+// CloseContext may not be called concurrently with Write, WriteContext, Close,
+// CloseContext or Written.
 func (w *WriteStream) CloseContext(ctx context.Context) error {
 	if w.s.transfers == nil {
 		return io.ErrClosedPipe

usb.go

@@ -246,7 +246,7 @@ func (c *Context) checkOpenDevs() error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if l := len(c.devices); l > 0 {
-		return fmt.Errorf("Context.Close called while %d Devices are still open, Close may be called only after all previously opened devices were successfuly closed.", l)
+		return fmt.Errorf("Context.Close called while %d Devices are still open, Close may be called only after all previously opened devices were successfuly closed", l)
 	}
 	return nil
 }