Corrected freed memory access on incoming EAPOL handling

For repeated/duplicated EAP-TLS messages it is possible that they arrive
after EAP-TLS is completed on BR. In this case they are handled by Initial
EAPOL-key handler and the message and handler are deleted right away. The
KMP receive message function however still referred to deleted handler
which caused freed memory access. This is now corrected.

source/Security/kmp/kmp_api.c

@@ -598,8 +598,7 @@ int8_t kmp_service_msg_if_receive(kmp_service_t *service, uint8_t instance_id, k
     int8_t ret = -1;
     if (kmp->sec_prot.receive != NULL) {
         ret = kmp->sec_prot.receive(&kmp->sec_prot, pdu, size);
-    }
-    if (kmp->sec_prot.conn_receive != NULL) {
+    } else if (kmp->sec_prot.conn_receive != NULL) {
         ret = kmp->sec_prot.conn_receive(&kmp->sec_prot, pdu, size, connection_num);
     }