[VOL-4478]  If a flow operation fails, the OLT adapter should return an error to the core.

Change-Id: Ie948e9a355ddf3838179a32112e4d17ae3f70b41
diff --git a/internal/pkg/core/openolt_flowmgr_test.go b/internal/pkg/core/openolt_flowmgr_test.go
index 45cd79e..7154225 100644
--- a/internal/pkg/core/openolt_flowmgr_test.go
+++ b/internal/pkg/core/openolt_flowmgr_test.go
@@ -1212,8 +1212,12 @@
 	defer cancel()
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			flowMgr[tt.args.intfID].checkAndAddFlow(ctx, tt.args.args, tt.args.classifierInfo, tt.args.actionInfo, tt.args.flow,
+			err := flowMgr[tt.args.intfID].checkAndAddFlow(ctx, tt.args.args, tt.args.classifierInfo, tt.args.actionInfo, tt.args.flow,
 				tt.args.TpInst, tt.args.gemPorts, tt.args.TpID, tt.args.uni)
+			if err != nil {
+				t.Error("check-and-add-flow failed", err)
+				return
+			}
 		})
 	}
 }