Only set the ipfilter running state to 'not running' if we are

doing the teardown.  ipf_destroy_all() may free ipfmain in case
of ipf_dynamic_softc being true, thus we are avoiding a possible
memory modified after free as well.

Reported by:	Coverity
Coverity CID:	1357320
Approved by:	re (hrs)
MFC after:	10 days

sys/contrib/ipfilter/netinet/mlfk_ipl.c

@@ -291,13 +291,14 @@ vnet_ipf_uninit(void)
 		return;
 
 	if (V_ipfmain.ipf_running >= 0) {
+
 		if (ipfdetach(&V_ipfmain) != 0)
 			return;
 
+		V_ipfmain.ipf_running = -2;
+
 		ipf_destroy_all(&V_ipfmain);
 	}
-
-	V_ipfmain.ipf_running = -2;
 }
 VNET_SYSUNINIT(vnet_ipf_uninit, SI_SUB_PROTO_FIREWALL, SI_ORDER_THIRD,
     vnet_ipf_uninit, NULL);