message: tools: fix clang-format error message
  This was hard-coded when it should not have been.
diff: @@ -33,14 +33,14 @@ if [[ $version =~ $semver_regex ]]; then
  version_major=${BASH_REMATCH[1]}
  if [ "$version_required_major" -gt "$version_major" ]; then
  echo "Clang version $version_major too old (required: $version_required_major)"
  - echo "You can use clang-format-12 from docker:"
  + echo "You can use clang-format-$version_required_major from docker:"
  echo ""
  echo " 'tools/run-docker.sh tools/fix_style.sh .'"
  exit 1
  elif [ "$version_required_major" -lt "$version_major" ]; then
  echo "Clang version $version_major too new (required: $version_required_major)"
  - echo "You can use clang-format-10 from docker:"
  + echo "You can use clang-format-$version_required_major from docker:"
  echo ""
  echo " 'tools/run-docker.sh tools/fix_style.sh .'"
  exit 1
  