coverity#735463 Dead default in switch

Change-Id: I422f11f1ccda36c00e00775b32772c1e827b6686

sc/source/filter/oox/workbookfragment.cxx

@@ -444,8 +444,9 @@ void WorkbookFragment::finalizeImport()
                             case SHEETTYPE_CHARTSHEET:
                                 xFragment.set( new ChartsheetFragment( *xSheetGlob, aFragmentPath ) );
                             break;
-                            default:
-                                OSL_ENSURE( false, "WorkbookFragment::finalizeImport - unexpected sheet type" );
+                            case SHEETTYPE_EMPTYSHEET:
+                            case SHEETTYPE_MODULESHEET:
+                                break;
                         }
 
                         // insert the fragment into the map