add comment about self talk

tests/unit/s2n_self_talk_inet_socket_test.c

@@ -176,6 +176,13 @@ static S2N_RESULT launch_test(const struct self_talk_inet_socket_callbacks *sock
     return S2N_RESULT_OK;
 }
 
+/* These test are unique compared to our other self talk tests because they are testing
+ * socket functionality. When enabled, kTLS offloads the TLS protocol to the socket so
+ * its necessary to use AF_INET sockets to test this functionality. Its not possible to
+ * enable kTLS on a AF_UNIX socket, which is what our other self talk test use. The use
+ * of AF_INET socket also drives the need to fork and create two process (client and
+ * server) to establish the connection.
+ */
 int main(int argc, char **argv)
 {
     BEGIN_TEST();