buttslock.sh not passing on shellcheck

[edumco]

While running make shellcheck the file buttslock.sh present error

eduardo@note:~/git/dockerfiles$ make shellcheck 
docker run --rm -i -t \
	--name df-shellcheck \
	-v /home/eduardo/git/dockerfiles:/usr/src:ro \
	--workdir /usr/src \
	r.j3ss.co/shellcheck ./shellcheck.sh
[OK]: sucessfully linted ./bashrc
[OK]: sucessfully linted ./bcc-tools/entrypoint.sh
[OK]: sucessfully linted ./build-all.sh

In ./buttslock/buttslock.sh line 19:
    -level 0%,100%,0.6 -blur $BLURTYPE $FONT \
                                       ^---^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    -level 0%,100%,0.6 -blur $BLURTYPE "$FONT" \

For more information:
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
[OK]: sucessfully linted ./distcc/distccd-init
[OK]: sucessfully linted ./firefox/entrypoint.sh
[OK]: sucessfully linted ./github-dev/cleanup-pr-branch
[OK]: sucessfully linted ./github-dev/release-email-notification
[OK]: sucessfully linted ./github-dev/upload-assets
[OK]: sucessfully linted ./gitiles/start.sh
[OK]: sucessfully linted ./gitserver/create_repo
[OK]: sucessfully linted ./gitserver/start.sh
[OK]: sucessfully linted ./kernel-builder/build_kernel
[OK]: sucessfully linted ./kvm/start.sh
[OK]: sucessfully linted ./latest-versions.sh
[OK]: sucessfully linted ./lkp-tests/runbench
[OK]: sucessfully linted ./mailgun/sendemail
[OK]: sucessfully linted ./metasploit/start.sh
[OK]: sucessfully linted ./mitmproxy/docker-entrypoint.sh
[OK]: sucessfully linted ./mpd/mpd.sh
[OK]: sucessfully linted ./mutt/entrypoint.sh
[OK]: sucessfully linted ./postfix/runit_bootstrap
[OK]: sucessfully linted ./postfix/service/postfix/run
[OK]: sucessfully linted ./postfix/service/rsyslog/run
[OK]: sucessfully linted ./radarr/entrypoint.sh
[OK]: sucessfully linted ./run.sh
[OK]: sucessfully linted ./runc-rootless/start.sh
[OK]: sucessfully linted ./shellcheck.sh
[OK]: sucessfully linted ./skype/run-skype-and-wait-for-exit
[OK]: sucessfully linted ./slapd/start.sh
[OK]: sucessfully linted ./sonarr/entrypoint.sh
[OK]: sucessfully linted ./sublime-text-3/run.sh
[OK]: sucessfully linted ./test.sh
[OK]: sucessfully linted ./tor-relay/run.sh
[OK]: sucessfully linted ./unifi/entrypoint.sh
[OK]: sucessfully linted ./vscode/start.sh
[OK]: sucessfully linted ./wireguard/install/entrypoint.sh
[OK]: sucessfully linted ./ykman/entrypoint.sh
[OK]: sucessfully linted ./ykpersonalize/entrypoint.sh
[OK]: sucessfully linted ./yubico-piv-tool/entrypoint.sh
These files failed shellcheck: ./buttslock/buttslock.sh
make: *** [Makefile:45: shellcheck] Error 1