ofz#13431 fix build

since

commit c600817e
Date:   Mon Feb 25 15:34:13 2019 +0200

    Make SdAbstractDialogFactory::Create() do its job also on non-DESKTOP

Change-Id: I95ff8ed3dc81ec542ac76d5f5bbd7582391c84a5

vcl/workben/cgmfuzzer.cxx

@@ -105,6 +105,11 @@ extern "C" void* lo_get_custom_widget_func(const char*)
     return nullptr;
 }
 
+extern "C" void* SdCreateDialogFactory()
+{
+    return nullptr;
+}
+
 extern "C" bool TestImportCGM(SvStream &rStream);
 
 extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)

vcl/workben/pptfuzzer.cxx

@@ -103,6 +103,11 @@ extern "C" void* lo_get_custom_widget_func(const char*)
     return nullptr;
 }
 
+extern "C" void* SdCreateDialogFactory()
+{
+    return nullptr;
+}
+
 extern "C" bool TestImportPPT(SvStream &rStream);
 
 extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)