reduce cost of OUString construction by avoiding
initialising a temporary and then overwriting it.
12s to 10s
Change-Id: I889152ba71947004ca7d5c96f073182c94d95ed5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175539
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>