avoid crashing when executing fw tests

Found while debugging an issue with several Verdict errors on kernel
6.17.x. Something has changed.

Author: gustavo-iniguez-goya

daemon/firewall/nftables/exprs/log_test.go

@@ -133,6 +133,7 @@ func TestExprLog(t *testing.T) {
 			r, _ := nftest.AddTestRule(t, conn, logExpr)
 			if r == nil {
 				t.Error("Error adding rule with log expression")
+				return
 			}
 
 			if !nftest.AreExprsValid(t, &test.TestsT, r) {

daemon/firewall/nftables/exprs/port_test.go

@@ -47,19 +47,23 @@ func TestExprPort(t *testing.T) {
 			r, _ := nftest.AddTestRule(t, conn, portExpr)
 			if r == nil {
 				t.Errorf("Error adding rule with port (%s) expression", test.port)
+				return
 			}
 			e := r.Exprs[0]
 			cmp, ok := e.(*expr.Cmp)
 			if !ok {
 				t.Errorf("%s - invalid port expr: %T", test.port, e)
+				return
 			}
 			//fmt.Printf("%s, %+v\n", reflect.TypeOf(e).String(), e)
 			if reflect.TypeOf(e).String() != "*expr.Cmp" {
 				t.Errorf("%s - first expression should be *expr.Cmp, instead of: %s", test.port, reflect.TypeOf(e))
+				return
 			}
 			portVal := binaryutil.BigEndian.PutUint16(uint16(test.portVal))
 			if !bytes.Equal(cmp.Data, portVal) {
 				t.Errorf("%s - invalid port in expr.Cmp: %d", test.port, cmp.Data)
+				return
 			}
 
 		})
@@ -94,11 +98,13 @@ func TestExprPortRange(t *testing.T) {
 			r, _ := nftest.AddTestRule(t, conn, portExpr)
 			if r == nil {
 				t.Errorf("Error adding rule with port range (%s) expression", test.port)
+				return
 			}
 			e := r.Exprs[0]
 			_, ok := e.(*expr.Range)
 			if !ok {
 				t.Errorf("%s - invalid port range expr: %T", test.port, e)
+				return
 			}
 			fmt.Printf("%s, %+v\n", reflect.TypeOf(e).String(), e)
 			if reflect.TypeOf(e).String() != "*expr.Range" {

daemon/firewall/nftables/exprs/quota_test.go

@@ -228,6 +228,7 @@ func TestExprQuota(t *testing.T) {
 			r, _ := nftest.AddTestRule(t, conn, quotaExpr)
 			if r == nil && !test.ExpectedFail {
 				t.Error("Error adding rule with Quota expression")
+				return
 			}
 
 			if !nftest.AreExprsValid(t, &test, r) {