vboot: Fixes bug in get_gbb_flags.sh -e

get_gbb_flags.sh outputs incorrect information because the hex number is not
parsed correctly.

BUG=none
TEST=Manual
BRANCH=none

Change-Id: Ie6428a5c50d48ae5d732b31d7a8e7b314653c2d9
Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2108286
Reviewed-by: Joel Kitching <kitching@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
diff --git a/scripts/image_signing/get_gbb_flags.sh b/scripts/image_signing/get_gbb_flags.sh
index a6aa89a..2b78af6 100755
--- a/scripts/image_signing/get_gbb_flags.sh
+++ b/scripts/image_signing/get_gbb_flags.sh
@@ -34,7 +34,7 @@
   # Keep 'local' declaration split from assignment so return code is checked.
   local gbb_flags
   gbb_flags="$(futility gbb -g --flags "${image_file}")"
-  local raw_gbb_flags="$(echo "${gbb_flags}" | egrep -o "0x[0-9]+")"
+  local raw_gbb_flags="$(echo "${gbb_flags}" | egrep -o "0x[0-9a-fA-F]+")"
   printf "Chrome OS GBB set ${gbb_flags}\n"
 
   if [ "${FLAGS_explicit}" = "${FLAGS_TRUE}" ]; then