loplugin:stringconstant: Flag more inefficiencies

Change-Id: I5bb3493e3d27bd348f58cd4f858f34becf761cd0

oox/source/export/chartexport.cxx

@@ -821,7 +821,7 @@ void ChartExport::exportExternalData( Reference< css::chart::XChartDocument > xC
         }
         FSHelperPtr pFS = GetFS();
         OUString type = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/package";
-        if (relationPath.endsWith(OUString(".bin")))
+        if (relationPath.endsWith(".bin"))
             type = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/oleObject";
 
         OUString sRelId = GetFB()->addRelation(pFS->getOutputStream(),

oox/source/export/vmlexport.cxx

@@ -197,7 +197,7 @@ bool VMLExport::IsWaterMarkShape(const OUString& rStr)
 {
      if (rStr.isEmpty() )  return false;
 
-     if (rStr.match(OUString("PowerPlusWaterMarkObject")) || rStr.match(OUString("WordPictureWatermark")))
+     if (rStr.match("PowerPlusWaterMarkObject") || rStr.match("WordPictureWatermark"))
         return true;
      else
         return false;