Fixed typo.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7466 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/exp-drd/tests/Makefile.am b/exp-drd/tests/Makefile.am
index ef89663..dea5931 100644
--- a/exp-drd/tests/Makefile.am
+++ b/exp-drd/tests/Makefile.am
@@ -62,7 +62,7 @@
         tc10_rec_lock.vgtest                                    \
         tc10_rec_lock.stderr.exp                                \
         tc11_XCHG.vgtest                                        \
-        tc11_XCHG.stderr.exp tc11_XCHG.stderr.exp               \
+        tc11_XCHG.stderr.exp tc11_XCHG.stdout.exp               \
         tc12_rwl_trivial.vgtest                                 \
         tc12_rwl_trivial.stderr.exp                             \
         tc13_laog1.vgtest                                       \