Fix uninitialized variable found by Maxime Villard's Brainy Code Scanner.
Fix uninitialized variable found by Maxime Villard's Brainy Code Scanner.

ok uebayasi@, mlarkin@

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