feat: standardize error for prompt

Signed-off-by: Alano Terblanche <18033717+Benehiko@users.noreply.github.com>

cli/command/plugin/testdata/plugin-upgrade-terminate.golden

@@ -1,2 +1,2 @@
 Upgrading plugin foo/bar from localhost:5000/foo/bar:v0.1.0 to localhost:5000/foo/bar:v1.0.0
-Plugin images do not match, are you sure? [y/N] 
+Plugin images do not match, are you sure? [y/N] 

cli/command/plugin/upgrade.go

@@ -8,6 +8,7 @@ import (
 	"github.com/distribution/reference"
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
+	"github.com/docker/docker/errdefs"
 	"github.com/docker/docker/pkg/jsonmessage"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -63,11 +64,12 @@ func runUpgrade(ctx context.Context, dockerCli command.Cli, opts pluginOptions)
 
 	fmt.Fprintf(dockerCli.Out(), "Upgrading plugin %s from %s to %s\n", p.Name, reference.FamiliarString(old), reference.FamiliarString(remote))
 	if !opts.skipRemoteCheck && remote.String() != old.String() {
-		if r, err := command.PromptForConfirmation(ctx, dockerCli.In(), dockerCli.Out(), "Plugin images do not match, are you sure?"); !r || err != nil {
-			if err != nil {
-				return errors.Wrap(err, "canceling upgrade request")
-			}
-			return errors.New("canceling upgrade request")
+		r, err := command.PromptForConfirmation(ctx, dockerCli.In(), dockerCli.Out(), "Plugin images do not match, are you sure?")
+		if err != nil {
+			return err
+		}
+		if !r {
+			return errdefs.Cancelled(errors.New("`plugin upgrade` has been cancelled"))
 		}
 	}
 

cli/command/plugin/upgrade_test.go

@@ -5,11 +5,9 @@ import (
 	"io"
 	"testing"
 
-	"github.com/docker/cli/cli/command"
 	"github.com/docker/cli/internal/test"
 	"github.com/docker/docker/api/types"
 	"github.com/pkg/errors"
-	"gotest.tools/v3/assert"
 	"gotest.tools/v3/golden"
 )
 
@@ -34,9 +32,6 @@ func TestUpgradePromptTermination(t *testing.T) {
 	// need to set a remote address that does not match the plugin
 	// reference sent by the `pluginInspectFunc`
 	cmd.SetArgs([]string{"foo/bar", "localhost:5000/foo/bar:v1.0.0"})
-	test.TerminatePrompt(ctx, t, cmd, cli, func(t *testing.T, err error) {
-		t.Helper()
-		assert.ErrorIs(t, err, command.ErrPromptTerminated)
-	})
+	test.TerminatePrompt(ctx, t, cmd, cli)
 	golden.Assert(t, cli.OutBuffer().String(), "plugin-upgrade-terminate.golden")
 }