net/sched: act_vlan: Test priority 0 modification

Because explicitly being set, the priority 0 should appear
in the output.
Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/tc-testing/tc-tests/actions/vlan.json

@@ -445,6 +445,30 @@
         "matchCount": "0",
         "teardown": []
     },
+    {
+        "id": "ba5b",
+        "name": "Add vlan modify action for protocol 802.1Q setting priority 0",
+        "category": [
+            "actions",
+            "vlan"
+        ],
+        "setup": [
+            [
+                "$TC actions flush action vlan",
+                0,
+                1,
+                255
+            ]
+        ],
+        "cmdUnderTest": "$TC actions add action vlan modify protocol 802.1Q id 5 priority 0 index 100",
+        "expExitCode": "0",
+        "verifyCmd": "$TC actions get action vlan index 100",
+        "matchPattern": "action order [0-9]+: vlan.*modify id 100 priority 0 protocol 802.1Q pipe.*index 100 ref",
+        "matchCount": "0",
+        "teardown": [
+            "$TC actions flush action vlan"
+        ]
+    },
     {
         "id": "6812",
         "name": "Add vlan modify action for protocol 802.1Q",