Update Changelog for fixes to X.509 sample apps
diff --git a/ChangeLog b/ChangeLog
index 8e25526..911f280 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -31,9 +31,9 @@
      a contribution from Tobias Tangemann. #541
    * Fixed cert_app sample program for debug output and for use when no root
      certificates are provided.
-   * Fixed sample application 'programs/pkey/gen_key.c' for builds where the
-     configuration MBEDTLS_PEM_WRITE_C is not defined. Found by inestlerode.
-     #559.
+   * Fixed the sample applications gen_key.c, cert_req.c and cert_write.c for
+     builds where the configuration MBEDTLS_PEM_WRITE_C is not defined. Found
+     by inestlerode. #559.
 
 Changes
    * Extended test coverage of special cases, and added new timing test suite.