tdf#57950: Replace chained O(U)StringBuffer::append() with operator+

Change-Id: Iae8e50864dbd90ff49a4fcc31a06b2158eab4afc
Reviewed-on: https://gerrit.libreoffice.org/14998Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>

oox/source/drawingml/chart/chartconverter.cxx

@@ -54,7 +54,7 @@ static OUString lclGenerateApiString( const OUString& rString )
     sal_Int32 nQuotePos = aRetString.getLength();
     while( (nQuotePos = aRetString.lastIndexOf( '"', nQuotePos )) >= 0 )
         aRetString = aRetString.replaceAt( nQuotePos, 1, "\"\"" );
-    return OUStringBuffer().append( '"' ).append( aRetString ).append( '"' ).makeStringAndClear();
+    return "\"" + aRetString + "\"";
 }
 
 static OUString lclGenerateApiArray( const Matrix< Any >& rMatrix )

sc/source/filter/oox/formulabase.cxx

@@ -1624,7 +1624,7 @@ OUString FormulaProcessorBase::generateApiString( const OUString& rString )
     sal_Int32 nQuotePos = aRetString.getLength();
     while( (nQuotePos = aRetString.lastIndexOf( '"', nQuotePos )) >= 0 )
         aRetString = aRetString.replaceAt( nQuotePos, 1, OUString( "\"\"" ) );
-    return OUStringBuffer().append( '"' ).append( aRetString ).append( '"' ).makeStringAndClear();
+    return "\"" + aRetString + "\"";
 }
 
 OUString FormulaProcessorBase::generateApiArray( const Matrix< Any >& rMatrix )