build-tools.sh: fix wrong variable names as reported by shellcheck - #3365

build-tools.sh: fix wrong variable names as reported by shellcheck#3365

lgirdwood merged 2 commits into

thesofproject:masterthesofproject/sof:masterfrom

marc-hb:shellcheck-build-toolsmarc-hb/sof:shellcheck-build-toolsCopy head branch name to clipboard