cbfstool: use struct cbfs_file * instead of void *

My concern was that compilers may something stupid under the assumption
of a fixed struct size, but filename is already variable, so things are
okay.

Change-Id: I5348faf68f0a7993294e9de4c0b6c737278b28af
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/11331
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed