add missing DoClose

Thanks to Daniel Bankston

Change-Id: Ieeff9d1a35f7abdab07bbe4eab459d89979e5402

sc/qa/unit/subsequent_filters-test.cxx

@@ -678,6 +678,8 @@ void ScFiltersTest::testSharedFormulaXLSX()
     {
         CPPUNIT_ASSERT(itr->second->GetType() & RT_SHARED);
     }
+
+    xDocSh->DoClose();
 }
 
 void ScFiltersTest::testCellValueXLSX()