hack: quote all parameters with variable interpolation

better safe then sorry. especially for rm

Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
Upstream-commit: ac20568b0a62c794c0f1190703f051bd1cfac341
Component: engine

components/engine/hack/dind

@@ -60,7 +60,7 @@ for HIER in $(cut -d: -f2 /proc/1/cgroup); do
 
 	mkdir -p "$CGROUP/$HIER"
 
-	if ! mountpoint -q $CGROUP/$HIER; then
+	if ! mountpoint -q "$CGROUP/$HIER"; then
 		mount -n -t cgroup -o "$OHIER" cgroup "$CGROUP/$HIER"
 	fi