tdf#112689: Replace chained O(U)StringBuffer::append() with operator+

Change-Id: I4446858ed30df4adffbf18ab609c95690cff99c0
Reviewed-on: https://gerrit.libreoffice.org/67668
Tested-by: Jenkins
Reviewed-by: Muhammet Kara <muhammet.kara@collabora.com>

chart2/source/tools/ObjectIdentifier.cxx

@@ -699,16 +699,12 @@ OUString ObjectIdentifier::createPieSegmentDragParameterString(
         , const awt::Point& rMinimumPosition
         , const awt::Point& rMaximumPosition )
 {
-    OUStringBuffer aRet( OUString::number( nOffsetPercent ) );
-    aRet.append( ',');
-    aRet.append( OUString::number( rMinimumPosition.X ) );
-    aRet.append( ',');
-    aRet.append( OUString::number( rMinimumPosition.Y ) );
-    aRet.append( ',');
-    aRet.append( OUString::number( rMaximumPosition.X ) );
-    aRet.append( ',');
-    aRet.append( OUString::number( rMaximumPosition.Y ) );
-    return aRet.makeStringAndClear();
+    OUString aRet = OUString::number( nOffsetPercent )
+                  + "," + OUString::number( rMinimumPosition.X )
+                  + "," + OUString::number( rMinimumPosition.Y )
+                  + "," + OUString::number( rMaximumPosition.X )
+                  + "," + OUString::number( rMaximumPosition.Y );
+    return aRet;
 }
 
 bool ObjectIdentifier::parsePieSegmentDragParameterString(