cmd/utils: don't enumerate USB unless --usb is set (#22130)

USB enumeration still occured. Make sure it will only occur if --usb is set.
This also deprecates the 'NoUSB' config file option in favor of a new option 'USB'.

node/config.go

@@ -95,6 +95,9 @@ type Config struct {
 	// NoUSB disables hardware wallet monitoring and connectivity.
 	NoUSB bool `toml:",omitempty"`
 
+	// USB enables hardware wallet monitoring and connectivity.
+	USB bool `toml:",omitempty"`
+
 	// SmartCardDaemonPath is the path to the smartcard daemon's socket
 	SmartCardDaemonPath string `toml:",omitempty"`
 
@@ -476,7 +479,7 @@ func makeAccountManager(conf *Config) (*accounts.Manager, string, error) {
 		// we can have both, but it's very confusing for the user to see the same
 		// accounts in both externally and locally, plus very racey.
 		backends = append(backends, keystore.NewKeyStore(keydir, scryptN, scryptP))
-		if !conf.NoUSB {
+		if conf.USB {
 			// Start a USB hub for Ledger hardware wallets
 			if ledgerhub, err := usbwallet.NewLedgerHub(); err != nil {
 				log.Warn(fmt.Sprintf("Failed to start Ledger hub, disabling: %v", err))