1.2.1 "Ensure a separate partition for containers has been created" doesn't work with userns

[AkihiroSuda]

docker-bench-security/tests/1_host_configuration.sh

Lines 68 to 86 in 6d73492

	# 1.2.1
	check_1_2_1() {
	id_1_2_1="1.2.1"
	desc_1_2_1="Ensure a separate partition for containers has been created"
	check_1_2_1="$id_1_2_1 - $desc_1_2_1"
	starttestjson "$id_1_2_1" "$desc_1_2_1"
	totalChecks=$((totalChecks + 1))
	if mountpoint -q -- "$(docker info -f '{{ .DockerRootDir }}')" >/dev/null 2>&1; then
	pass "$check_1_2_1"
	resulttestjson "PASS"
	currentScore=$((currentScore + 1))
	else
	warn "$check_1_2_1"
	resulttestjson "WARN"
	currentScore=$((currentScore - 1))
	fi
	}

This check fails when /var/lib/docker has a dedicated partition but userns-remap is enabled, because .DockerRootDir is like /var/lib/docker/296608.296608, not /var/lib/docker

[konstruktoid]

Duplicate of #332