vboot: Remove unnecessary flag unset operations

Since all flags are initialized as 0 in vb2api_init(),
some flag unset operations are not needed.

Edit few comments to make it more accurate.

BUG=none
TEST=export CC=x86_64-pc-linux-gnu-clang DEBUG=1; \
     make -j32 test_setup && make -j32 runtests;
BRANCH=none

Signed-off-by: edisonhello <edisonhello@google.com>
Change-Id: I0129f43342598195800ff671b965100d3d568564
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3066803
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
4 files changed