It does the opposite to "expand", removing a trailing empty file from
CBFS. It also returns the size of the CBFS post processing on stdout.
BUG=b:65853903
BRANCH=none
TEST=`cbfstool test.bin truncate -r FW_MAIN_A` removes the trailing
empty file in FW_MAIN_A. Without a trailing empty file, the region is
left alone (tested using COREBOOT which comes with a master header
pointer).
Change-Id: I0c747090813898539f3428936afa9d8459adee9c
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/21608
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>