Fix antctl trace-packet arguments missing issue

Fix the following error when running `antctl trace-packet`, which is
caused by missing arguments for ovs-appctl command.

```
syntax error at br-int (or the bridge name was omitted)
ovs-appctl: /var/run/openvswitch/ovs-vswitchd.103.ctl: server returned an error
```

Signed-off-by: Lan Luo <luola@vmware.com>

pkg/agent/apiserver/handlers/ovstracing/handler.go

@@ -356,7 +356,7 @@ func validateRequest(r *http.Request) (*request, *handlers.HandlerError) {
 	return &request, nil
 }
 
-// HandleFunc returns the function which can handle API requests to "/ovsflows".
+// HandleFunc returns the function which can handle API requests to "/ovstracing".
 func HandleFunc(aq querier.AgentQuerier) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		var traceReq *ovsctl.TracingRequest

pkg/ovs/ovsctl/appctl.go

@@ -38,6 +38,7 @@ func (r *ovsAppctlRunner) RunAppctlCmd(cmd string, needsBridge bool, args ...str
 	if needsBridge {
 		cmdArgs = append(cmdArgs, r.bridge)
 	}
+	cmdArgs = append(cmdArgs, args...)
 	ovsCmd := exec.CommandContext(context.TODO(), "ovs-appctl", cmdArgs...)
 	out, err := ovsCmd.CombinedOutput()
 	if err != nil {