accounts/usbwallet: simplify code using -= operator (#17904)

accounts/usbwallet/ledger.go

@@ -350,7 +350,7 @@ func (w *ledgerDriver) ledgerSign(derivationPath []uint32, tx *types.Transaction
 		signer = new(types.HomesteadSigner)
 	} else {
 		signer = types.NewEIP155Signer(chainID)
-		signature[64] = signature[64] - byte(chainID.Uint64()*2+35)
+		signature[64] -= byte(chainID.Uint64()*2 + 35)
 	}
 	signed, err := tx.WithSignature(signer, signature)
 	if err != nil {

accounts/usbwallet/trezor.go

@@ -221,7 +221,7 @@ func (w *trezorDriver) trezorSign(derivationPath []uint32, tx *types.Transaction
 		signer = new(types.HomesteadSigner)
 	} else {
 		signer = types.NewEIP155Signer(chainID)
-		signature[64] = signature[64] - byte(chainID.Uint64()*2+35)
+		signature[64] -= byte(chainID.Uint64()*2 + 35)
 	}
 	// Inject the final signature into the transaction and sanity check the sender
 	signed, err := tx.WithSignature(signer, signature)