fix the sw_swdoc_test crash

Keeping a reference to an expired temporary is a rather bad idea.

Change-Id: I4d93d644b7db957ea49bcf1127647b7e5427f469

sw/inc/swscanner.hxx

@@ -38,7 +38,7 @@ class SwScanner
     const rtl::OUString aPreDashReplacementText;
     rtl::OUString aText;
     const LanguageType* pLanguage;
-    const ModelToViewHelper& rConversionMap;
+    const ModelToViewHelper rConversionMap;
     sal_Int32 nStartPos;
     sal_Int32 nEndPos;
     sal_Int32 nBegin;