Add function name to changelog

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/ChangeLog.d/mbedtls_ecp_export.txt b/ChangeLog.d/mbedtls_ecp_export.txt
index 50fa0b3..4b5d7d4 100644
--- a/ChangeLog.d/mbedtls_ecp_export.txt
+++ b/ChangeLog.d/mbedtls_ecp_export.txt
@@ -1,3 +1,3 @@
 Features
-   * Add a function to export ECP keypair parameters.
-     Fixes #4838.
+   * Add mbedtls_ecp_export() function to export ECP
+     keypair parameters. Fixes #4838.