use fmt pkg for Errorf methods

Signed-off-by: James Sheppard <jgsheppa@protonmail.com>

cmd/helm/repo_add.go

@@ -178,7 +178,7 @@ func (o *repoAddOptions) run(out io.Writer) error {
 
 	// Check if the repo name is legal
 	if strings.Contains(o.name, "/") {
-		return errors.Errorf("repository name (%s) contains '/', please specify a different name without '/'", o.name)
+		return fmt.Errorf("repository name (%s) contains '/', please specify a different name without '/'", o.name)
 	}
 
 	// If the repo exists do one of two things:
@@ -190,7 +190,7 @@ func (o *repoAddOptions) run(out io.Writer) error {
 
 			// The input coming in for the name is different from what is already
 			// configured. Return an error.
-			return errors.Errorf("repository name (%s) already exists, please specify a different name", o.name)
+			return fmt.Errorf("repository name (%s) already exists, please specify a different name", o.name)
 		}
 
 		// The add is idempotent so do nothing