hush: add a TODO about redir3.tests failure

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/hush_test/hush-redir/redir3.right b/shell/hush_test/hush-redir/redir3.right
new file mode 100644
index 0000000..fd641a8
--- /dev/null
+++ b/shell/hush_test/hush-redir/redir3.right
@@ -0,0 +1,3 @@
+TEST
+./redir3.tests: line 4: 9: Bad file descriptor
+Output to fd#9: 1