Don't calculate 'total_len' twice.
Don't calculate 'total_len' twice.

Inspired by NetBSD' rtk(4) driver.

From: Mike Pechkin <mpech at mail dot ru>

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars