adjust test

tests/shtest

@@ -280,16 +280,16 @@ grep "Expected string key after ',' in object, not '\\['" $d/err > /dev/null
 # output
 cat <<EOF | (cd $d; $VALGRIND $Q $JQ -r 'to_entries[] | _experimental_output(.key;.value) | .key' >keys)
 {
-  "a.json": "aaa",
+  "a.txt": "aaa",
   "b/b.json": "invalid",
   "c/c.json": ["not","valid"],
   "d.json": {"e":10},
   "f.json": 8
 }
 EOF
-(cd $d; cat $(cat keys) keys) > $d/out || true
+(cd $d; ! cat $(cat keys) keys >out)
 cat > $d/expected <<'EOF'
-aaa{"e":10}8a.json
+aaa{"e":10}8a.txt
 b/b.json
 c/c.json
 d.json