cli/command/image: runBuild: inline vars and minor cleanups

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 9e646f6d92)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/image/build.go

@@ -184,7 +184,6 @@ func (out *lastProgressOutput) WriteProgress(prog progress.Progress) error {
 //nolint:gocyclo
 func runBuild(ctx context.Context, dockerCli command.Cli, options buildOptions) error {
 	var (
-		err           error
 		buildCtx      io.ReadCloser
 		dockerfileCtx io.ReadCloser
 		contextDir    string
@@ -266,7 +265,7 @@ func runBuild(ctx context.Context, dockerCli command.Cli, options buildOptions)
 		}
 
 		if err := build.ValidateContextDirectory(contextDir, excludes); err != nil {
-			return errors.Wrap(err, "error checking context")
+			return errors.Wrap(err, "checking context")
 		}
 
 		// And canonicalize dockerfile name to a platform-independent one
@@ -353,7 +352,6 @@ func runBuild(ctx context.Context, dockerCli command.Cli, options buildOptions)
 		}
 	}
 	buildOpts := imageBuildOptions(dockerCli, options)
-	buildOpts.Version = buildtypes.BuilderV1
 	buildOpts.Dockerfile = relDockerfile
 	buildOpts.AuthConfigs = authConfigs
 	buildOpts.RemoteContext = remote
@@ -363,7 +361,6 @@ func runBuild(ctx context.Context, dockerCli command.Cli, options buildOptions)
 		if options.quiet {
 			_, _ = fmt.Fprintf(dockerCli.Err(), "%s", progBuff)
 		}
-		cancel()
 		return err
 	}
 	defer response.Body.Close()
@@ -380,7 +377,8 @@ func runBuild(ctx context.Context, dockerCli command.Cli, options buildOptions)
 
 	err = jsonstream.Display(ctx, response.Body, streams.NewOut(buildBuff), jsonstream.WithAuxCallback(aux))
 	if err != nil {
-		if jerr, ok := err.(*jsonstream.JSONError); ok {
+		var jerr *jsonstream.JSONError
+		if errors.As(err, &jerr) {
 			// If no error code is set, default to 1
 			if jerr.Code == 0 {
 				jerr.Code = 1
@@ -544,6 +542,7 @@ func replaceDockerfileForContentTrust(ctx context.Context, inputTarStream io.Rea
 func imageBuildOptions(dockerCli command.Cli, options buildOptions) buildtypes.ImageBuildOptions {
 	configFile := dockerCli.ConfigFile()
 	return buildtypes.ImageBuildOptions{
+		Version:        buildtypes.BuilderV1,
 		Memory:         options.memory.Value(),
 		MemorySwap:     options.memorySwap.Value(),
 		Tags:           options.tags.GetSlice(),