shellcheck: chutney-git-bisect.sh issues
Shellcheck (https://github.com/koalaman/shellcheck) finds the following issues:
In chutney-git-bisect.sh line 23:
cd "$2"
^-- SC2164: Use 'cd ... || exit' or 'cd ... || return' in case cd fails.
In chutney-git-bisect.sh line 57:
i=$[$i+1]
^-- SC2007: Use $((..)) instead of deprecated $[..]
In chutney-git-bisect.sh line 60:
i=$[$i-1]
^-- SC2007: Use $((..)) instead of deprecated $[..]