[newlib-cygwin] Add release message for commit 9409c53

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=1f02aa08d1c9510f87c329a6fce2932e9df1fc9e

commit 1f02aa08d1c9510f87c329a6fce2932e9df1fc9e
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Wed Apr 20 12:34:07 2016 +0200

    Add release message for commit 9409c53

Diff:
---
 winsup/cygwin/release/2.5.1 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/winsup/cygwin/release/2.5.1 b/winsup/cygwin/release/2.5.1
index d0331fb..c9d3b61 100644
--- a/winsup/cygwin/release/2.5.1
+++ b/winsup/cygwin/release/2.5.1
@@ -16,3 +16,7 @@ Bug Fixes
 - Fix bug introduced in 2.5.0: Fix condition specifying when to write a
   NULL SID ACE.
   Addresses: https://cygwin.com/ml/cygwin/2016-04/msg00400.html
+
+- Remove spurious checks for already initialized pthread object in pthread
+  object init functions.
+  Addresses: https://cygwin.com/ml/cygwin/2016-04/msg00473.html