test with iptables-nft

Signed-off-by: Kyle Harding <kyle@balena.io>

test/healthcheck.sh

@@ -75,7 +75,6 @@ case $(id -u) in
     if command -v iptables-legacy >/dev/null 2>&1; then
         iptables-legacy -V
         iptables-legacy -L
-        iptables-legacy -A INPUT -p tcp --dport 9999 -j ACCEPT -m comment --comment "Test rule for ipt_comment module"
     fi
 
     if command -v iptables-nft >/dev/null 2>&1; then
@@ -84,6 +83,7 @@ case $(id -u) in
         iptables-nft -N DOCKER-ISOLATION-STAGE-1
         iptables-nft -L
         iptables-nft -I DOCKER-ISOLATION-STAGE-1 -j RETURN
+        iptables-nft -A INPUT -p tcp --dport 9999 -j ACCEPT -m comment --comment "Test rule for ipt_comment module"
     fi
     ;;
 *) ;;
@@ -93,7 +93,7 @@ case $(uname -m) in
 x86_64)
     ls -l /dev/kvm
     test -w /dev/kvm || test "$(id -u)" != 0
-    if which kvm-ok >/dev/null; then
+    if command -v kvm-ok >/dev/null 2>&1; then
         kvm-ok
     fi
     ;;