Representing a (non-negative) length with a signed integer is not optimal, so change its type to `size_t`. Change-Id: Ic0c2b7e081ba32d917409568ee53007d9ab7f8f3 Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-on: http://review.coreboot.org/4768 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>