Allow pxeboot to compile with gcc3.
Allow pxeboot to compile with gcc3.

Found by various (thanks!), fix originally from naddy@.  Prodded by espie@.

ok deraadt@

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