util: pass layer into firewall query callback

Some of the query callbacks want to know the firewall layer that was
being used for triggering the query to avoid duplicating that data.

Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

tests/virfirewalltest.c

@@ -990,11 +990,12 @@ testFirewallQueryHook(const char *const*args,
 
 static int
 testFirewallQueryCallback(virFirewallPtr fw,
+                          virFirewallLayer layer,
                           const char *const *lines,
                           void *opaque ATTRIBUTE_UNUSED)
 {
     size_t i;
-    virFirewallAddRule(fw, VIR_FIREWALL_LAYER_IPV4,
+    virFirewallAddRule(fw, layer,
                        "-A", "INPUT",
                        "--source-host", "!192.168.122.129",
                        "--jump", "REJECT", NULL);