Improve Changelog

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/ChangeLog.d/fix_some_resource_leaks.txt b/ChangeLog.d/fix_some_resource_leaks.txt
index 352e2ba..fcc9086 100644
--- a/ChangeLog.d/fix_some_resource_leaks.txt
+++ b/ChangeLog.d/fix_some_resource_leaks.txt
@@ -1,4 +1,6 @@
 Bugfix
-   * Fixed resource leaks in mbedtls_pk_parse_public_key(), 
-     mbedtls_ssl_cache_set() for certain error conditions,
-     flagged by a static analyzer.
+   * Fixed resource leaks in mbedtls_pk_parse_public_key() under
+     certain error conditions.
+Security
+   * Fix potential memory leak inside mbedtls_ssl_cache_set() with
+     invalid session id len.