lib21: always append '\0' in vb2_readfile For utilities reading text file, it is easier to process as ASCIIZ input if vb2_readfile can always return a buffer ends with '\0' so we don't need to pass and check the size. BUG=None TEST=make clean && make runtests BRANCH=None Signed-off-by: Hung-Te Lin <[email protected]> Change-Id: Ib6294969fb325b9b7899e6295fb1817ad91a9952 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2426092 Reviewed-by: Joel Kitching <[email protected]> (cherry picked from commit 7c6bf3080a20077f1da49bc383297ac33bce35f8) Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2514762 Reviewed-by: Evan Green <[email protected]> Commit-Queue: Karthikeyan Ramasubramanian <[email protected]> Tested-by: Karthikeyan Ramasubramanian <[email protected]>