Update the location of defragmentation limitations

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/ChangeLog.d/tls-hs-defrag-in.txt b/ChangeLog.d/tls-hs-defrag-in.txt
index 748f95c..6bab02a 100644
--- a/ChangeLog.d/tls-hs-defrag-in.txt
+++ b/ChangeLog.d/tls-hs-defrag-in.txt
@@ -4,4 +4,4 @@
      some servers, especially with TLS 1.3 in practice. There are a few
      limitations, notably a fragmented ClientHello is only supported when
      TLS 1.3 support is enabled. See the documentation of
-     mbedtls_ssl_conf_max_frag_len() for details.
+     mbedtls_ssl_handshake() for details.