Fix compiler warnings on iOS

ChangeLog

diff --git a/ChangeLog b/ChangeLog
index 39a039a..30b9846 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,7 @@
    * ssl_close_notify() could send more than one message in some circumstances
      with non-blocking I/O.
    * x509_crt_parse() did not increase total_failed on PEM error
+   * Fix compiler warnings on iOS (found by Sander Niemeijer).
 
 Changes
    * X.509 certificates with more than one AttributeTypeAndValue per