selftests/tc-testing: Create tests trying to add children to clsact/ingress qdiscs

In response to Wang's bug report [1], add the following test cases:

- Try and fail to add an fq child to an ingress qdisc
- Try and fail to add an fq child to a clsact qdisc

[1] https://lore.kernel.org/netdev/[email protected]/

Reviewed-by: Pedro Tammela <[email protected]>
Acked-by: Jamal Hadi Salim <[email protected]>
Signed-off-by: Victor Nogueira <[email protected]>
Reviewed-by: Cong Wang <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: vbnogueira

tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json

@@ -961,5 +961,49 @@
         "teardown": [
             "$TC qdisc del dev $DUMMY root"
         ]
+    },
+    {
+        "id": "4989",
+        "name": "Try to add an fq child to an ingress qdisc",
+        "category": [
+            "qdisc",
+            "ingress"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "$TC qdisc add dev $DUMMY handle ffff:0 ingress"
+        ],
+        "cmdUnderTest": "$TC qdisc add dev $DUMMY parent ffff:0 handle ffe0:0 fq",
+        "expExitCode": "2",
+        "verifyCmd": "$TC -j qdisc ls dev $DUMMY handle ffe0:",
+        "matchJSON": [],
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY ingress"
+        ]
+    },
+    {
+        "id": "c2b0",
+        "name": "Try to add an fq child to a clsact qdisc",
+        "category": [
+            "qdisc",
+            "ingress"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "$TC qdisc add dev $DUMMY handle ffff:0 clsact"
+        ],
+        "cmdUnderTest": "$TC qdisc add dev $DUMMY parent ffff:0 handle ffe0:0 fq",
+        "expExitCode": "2",
+        "verifyCmd": "$TC -j qdisc ls dev $DUMMY handle ffe0:",
+        "matchJSON": [],
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY clsact"
+        ]
     }
 ]