drivers/ec/vboot_auxfw: Reduce indentation with early return

BUG=none
TEST=emerge-geralt depthcharge
BRANCH=none

Change-Id: Ia75bdcadf2dfa5b001f62ca151d21ed66fe6325c
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/depthcharge/+/5691210
Reviewed-by: Julius Werner <jwerner@chromium.org>
1 file changed