buildgcc: Fix function prototype in GCC

With some newer versions of GCC (experienced with GCC 6.2.1 on Arch-
Linux) the first stage of a boostrapping fails due to a mismatching
function prototype. Also add a missing `static` to the signature.

Change-Id: Ia927036ccd725550f1191890515578bc80c74f80
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/17704
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed