[security-review] issue-10: refactor error-invalid-jump in bus-mapping

[silathdiir]

Description

Reference security review validated issue-10:

This code:

let is_jumpi = geth_step.op == OpcodeId::JUMPI;
let mut condition: Word = Word::zero();
if is_jumpi {
	condition = geth_step.stack.nth_last(1)?;
}
if is_jumpi {
	state.stack_read(
		&mut exec_step,
		geth_step.stack.nth_last_filled(1),
		condition,
	)?;
}

Could be replace by:

if geth_step.op == OpcodeId::JUMPI {
	state.stack_read(
		&mut exec_step,
		geth_step.stack.nth_last_filled(1),
		geth_step.stack.nth_last(1)?,
	)?;
}