Fix typo singing -> signing

cmd/helm/upgrade.go

@@ -108,7 +108,7 @@ func newUpgradeCmd(client helm.Interface, out io.Writer) *cobra.Command {
 	f.BoolVar(&upgrade.disableHooks, "disable-hooks", false, "disable pre/post upgrade hooks. DEPRECATED. Use no-hooks")
 	f.BoolVar(&upgrade.disableHooks, "no-hooks", false, "disable pre/post upgrade hooks")
 	f.BoolVar(&upgrade.verify, "verify", false, "verify the provenance of the chart before upgrading")
-	f.StringVar(&upgrade.keyring, "keyring", defaultKeyring(), "path to the keyring that contains public singing keys")
+	f.StringVar(&upgrade.keyring, "keyring", defaultKeyring(), "path to the keyring that contains public signing keys")
 	f.BoolVarP(&upgrade.install, "install", "i", false, "if a release by this name doesn't already exist, run an install")
 	f.StringVar(&upgrade.namespace, "namespace", "default", "namespace to install the release into (only used if --install is set)")
 	f.StringVar(&upgrade.version, "version", "", "specify the exact chart version to use. If this is not specified, the latest version is used")