GH-50773: [CI][Dev] Fix shellcheck errors in the ci/scripts/r_sanitize.sh - #50775

GH-50773: [CI][Dev] Fix shellcheck errors in the ci/scripts/r_sanitize.sh#50775

kou merged 2 commits into

apache:mainapache/arrow:mainfrom

hiroyuki-sato:topic/shellcheck-r_sanitizehiroyuki-sato/arrow:topic/shellcheck-r_sanitizeCopy head branch name to clipboard