cli/command: PromptUserForCredentials: use consts for all hints

This message resulted in code-lines that were too long; move it to a
const together with the other hint. While at it, also suppress unhandled
error, and touch-up the code-comment.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

cli/command/registry.go

@@ -18,9 +18,13 @@ import (
 	"github.com/pkg/errors"
 )
 
-const patSuggest = "You can log in with your password or a Personal Access " +
-	"Token (PAT). Using a limited-scope PAT grants better security and is required " +
-	"for organizations using SSO. Learn more at https://docs.docker.com/go/access-tokens/"
+const (
+	registerSuggest = "Log in with your Docker ID or email address to push and pull images from Docker Hub. " +
+		"If you don't have a Docker ID, head over to https://hub.docker.com/ to create one."
+	patSuggest = "You can log in with your password or a Personal Access " +
+		"Token (PAT). Using a limited-scope PAT grants better security and is required " +
+		"for organizations using SSO. Learn more at https://docs.docker.com/go/access-tokens/"
+)
 
 // RegistryAuthenticationPrivilegedFunc returns a RequestPrivilegeFunc from the specified registry index info
 // for the given command.
@@ -126,8 +130,10 @@ func PromptUserForCredentials(ctx context.Context, cli Cli, argUser, argPassword
 	argUser = strings.TrimSpace(argUser)
 	if argUser == "" {
 		if serverAddress == registry.IndexServer {
-			// if this is a default registry (docker hub), then display the following message.
-			fmt.Fprintln(cli.Out(), "Log in with your Docker ID or email address to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com/ to create one.")
+			// When signing in to the default (Docker Hub) registry, we display
+			// hints for creating an account, and (if hints are enabled), using
+			// a token instead of a password.
+			_, _ = fmt.Fprintln(cli.Out(), registerSuggest)
 			if hints.Enabled() {
 				fmt.Fprintln(cli.Out(), patSuggest)
 				fmt.Fprintln(cli.Out())