remove a use of OUString::intern()
remove a use of OUString::intern()

maIconCache is defined as a std::unordered_map
'interning' a OUString to give to it as a key seems completely
superfluous since no-one will ever use it by address, even less
compare the address.

Change-Id: Iab5d106d7d51fcdfbd0a0dfd50ae28d686b9b2b7
Reviewed-on: https://gerrit.libreoffice.org/15692
Tested-by: Jenkins <5a4fe08359c7f97380e408c717ef42c86939cd86@libreoffice.org>
Reviewed-by: Caolán McNamara <301f5784f9f6aac04077f24f1e5abc31af69d401@redhat.com>
Tested-by: Caolán McNamara <301f5784f9f6aac04077f24f1e5abc31af69d401@redhat.com>

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core