This commit removes some ::rtl:: prefixes and RTL_CONSTASCII_STRINGPARAM,
 RTL_CONSTASCII_USTRINGPARAM macros in IO.

Change-Id: I410016990579e4a05843cfe396832a5fc8435e70
Signed-off-by: José Guilherme Vanz <guilherme.sft@gmail.com>
Reviewed-on: https://gerrit.libreoffice.org/1210Reviewed-by: Olivier Hallot <olivier.hallot@alta.org.br>
Tested-by: Olivier Hallot <olivier.hallot@alta.org.br>