drd: Add a suppression pattern

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11919 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/glibc-2.X-drd.supp b/glibc-2.X-drd.supp
index 441e7a8..b36a101 100644
--- a/glibc-2.X-drd.supp
+++ b/glibc-2.X-drd.supp
@@ -24,6 +24,11 @@
    drd:ConflictingAccess
    obj:/lib*/libc-*
 }
+{
+   drd-libc-thread-cancellation-test
+   drd:ConflictingAccess
+   fun:write
+}
 
 #
 # Suppression patterns for libstdc++, the implementation of the standard C++