[xen] add bug reference to changelog for previous commit

[myoung]

commit 6aac2a4a6287b27f3e26227de7e4137503faf9e7
Author: Michael Young <m.a.young at durham.ac.uk>
Date:   Tue Aug 7 22:37:10 2012 +0100

    add bug reference to changelog for previous commit

 xen.spec |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/xen.spec b/xen.spec
index c0e1ec1..324920f 100644
--- a/xen.spec
+++ b/xen.spec
@@ -721,7 +721,7 @@ rm -rf %{buildroot}
 %changelog
 * Tue Aug 07 2012 Michael Young <m.a.young at durham.ac.uk> - 4.1.2-25
 - remove some unnecessary cache flushing that slow things down
-- change python options on xend to reduce selinux problems
+- change python options on xend to reduce selinux problems (#845444)
 
 * Thu Jul 26 2012 Michael Young <m.a.young at durham.ac.uk> - 4.1.2-24
 - in rare circumstances an unprivileged user can crash an HVM guest