more LWIP_NOASSERT fixes
diff --git a/src/apps/httpd/httpd.c b/src/apps/httpd/httpd.c
index 2c836c8..bdffee3 100644
--- a/src/apps/httpd/httpd.c
+++ b/src/apps/httpd/httpd.c
@@ -2562,6 +2562,7 @@
   tcp_setprio(pcb, HTTPD_TCP_PRIO);
   /* set SOF_REUSEADDR here to explicitly bind httpd to multiple interfaces */
   err = tcp_bind(pcb, IP_ANY_TYPE, HTTPD_SERVER_PORT);
+  LWIP_UNUSED_ARG(err); /* in case of LWIP_NOASSERT */
   LWIP_ASSERT("httpd_init: tcp_bind failed", err == ERR_OK);
   pcb = tcp_listen(pcb);
   LWIP_ASSERT("httpd_init: tcp_listen failed", pcb != NULL);
diff --git a/src/apps/mdns/mdns.c b/src/apps/mdns/mdns.c
index 631e2ce..14334fc 100644
--- a/src/apps/mdns/mdns.c
+++ b/src/apps/mdns/mdns.c
@@ -1820,6 +1820,7 @@
   mdns_pcb->ttl = MDNS_TTL;
 #endif
   res = udp_bind(mdns_pcb, IP_ANY_TYPE, MDNS_PORT);
+  LWIP_UNUSED_ARG(res); /* in case of LWIP_NOASSERT */
   LWIP_ASSERT("Failed to bind pcb", res == ERR_OK);
   udp_recv(mdns_pcb, mdns_recv, NULL);
 
diff --git a/src/apps/snmp/snmp_threadsync.c b/src/apps/snmp/snmp_threadsync.c
index 858c40e..204f265 100644
--- a/src/apps/snmp/snmp_threadsync.c
+++ b/src/apps/snmp/snmp_threadsync.c
@@ -211,6 +211,7 @@
   err_t err = sys_mutex_new(&instance->sem_usage_mutex);
   LWIP_ASSERT("Failed to set up mutex", err == ERR_OK);
   err = sys_sem_new(&instance->sem, 0);
+  LWIP_UNUSED_ARG(err); /* in case of LWIP_NOASSERT */
   LWIP_ASSERT("Failed to set up semaphore", err == ERR_OK);
   instance->sync_fn = sync_fn;
 }