changed variable aResult to use concationation operator + instead of +=

Change-Id: I1547a869a9b6ede6e64727a1048232caf404acb7
Reviewed-on: https://gerrit.libreoffice.org/43340Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Muhammet Kara <muhammet.kara@pardus.org.tr>