Improve comments

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 0aa9f39..8964adc 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -201,7 +201,7 @@
     return -1;
 }
 
-/* Insert an empty record at the given offset. If offset is negative,
+/* Insert a (dummy) record at the given offset. If offset is negative,
  * count from the end of the first record. */
 static int recombine_insert_record(mbedtls_test_ssl_buffer *buf,
                                    int offset,
@@ -3251,6 +3251,8 @@
         }
     }
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+    /* A default TLS 1.3 handshake has only 1 flight from the server,
+     * while the default (non-resumption) 1.2 handshake has two. */
     if (version >= MBEDTLS_SSL_VERSION_TLS1_3 &&
         goal_state >= MBEDTLS_SSL_HANDSHAKE_OVER) {
         TEST_EQUAL(ret, 0);