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

Change-Id: Ieb5c1e13ae647b49fd563f1759d744bd5f008ce1
Reviewed-on: https://gerrit.libreoffice.org/65758
Tested-by: Jenkins
Reviewed-by: Muhammet Kara <muhammet.kara@collabora.com>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

basic/source/comp/exprtree.cxx

@@ -140,9 +140,8 @@ static SbiSymDef* AddSym ( SbiToken eTok, SbiSymPool& rPool, SbiExprType eCurExp
             // generate dummy parameters
             for( sal_Int32 n = 1; n <= pPar->GetSize(); n++ )
             {
-                OUStringBuffer aPar("PAR");
-                aPar.append(n);
-                pProc->GetParams().AddSym( aPar.makeStringAndClear() );
+                OUString aPar = "PAR" + OUString::number( n );
+                pProc->GetParams().AddSym( aPar );
             }
         }
     }