t1400 (update-ref): use test_must_fail

diff --git a/t/t1000-read-tree-m-3way.sh b/t/t1000-read-tree-m-3way.sh
index 4f171722d9e1dda7668f54b4104267eb70d91c67..ca8a4098fa06afbdbe5c427983d3953550457bc2 100755 (executable)
--- a/t/t1000-read-tree-m-3way.sh
+++ b/t/t1000-read-tree-m-3way.sh
@@ -309,7 +309,7 @@ test_expect_success \
 test_expect_success \
     '6 - must not exist in O && !A && !B case' "
      rm -f .git/index DD &&
-     echo DD >DD
+     echo DD >DD &&
      git update-index --add DD &&
      test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "