Update uninstall script to remove mount point path after umount (#2542)

install.sh

@@ -606,14 +606,17 @@ getshims() {
 
 killtree $({ set +x; } 2>/dev/null; getshims; set -x)
 
-do_unmount() {
-    awk -v path="$1" '$2 ~ ("^" path) { print $2 }' /proc/self/mounts | sort -r | xargs -r -t -n 1 umount
+do_unmount_and_remove() {
+    awk -v path="$1" '$2 ~ ("^" path) { print $2 }' /proc/self/mounts | sort -r | xargs -r -t -n 1 sh -c 'umount "$0" && rm -rf "$0"'
 }
 
-do_unmount '/run/k3s'
-do_unmount '/var/lib/rancher/k3s'
-do_unmount '/var/lib/kubelet/pods'
-do_unmount '/run/netns/cni-'
+do_unmount_and_remove '/run/k3s'
+do_unmount_and_remove '/var/lib/rancher/k3s'
+do_unmount_and_remove '/var/lib/kubelet/pods'
+do_unmount_and_remove '/run/netns/cni-'
+
+# Remove CNI namespaces
+ip netns show 2>/dev/null | grep cni- | xargs -r -t -n 1 ip netns delete
 
 # Delete network interface(s) that match 'master cni0'
 ip link show 2>/dev/null | grep 'master cni0' | while read ignore iface ignore; do