aDBFColumn.db_typ is input controlled

so we can't guarantee that it is valid ascii

Change-Id: Icdc6162db4405df729e548a836de5662255088ed
(cherry picked from commit 7e0b90af)
Reviewed-on: https://gerrit.libreoffice.org/16779Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

connectivity/source/drivers/dbase/DTable.cxx

@@ -345,7 +345,7 @@ void ODbaseTable::fillColumns()
         char cType[2];
         cType[0] = aDBFColumn.db_typ;
         cType[1] = 0;
-        aTypeName = OUString::createFromAscii(cType);
+        aTypeName = OUString(cType, 1, RTL_TEXTENCODING_ASCII_US);
         SAL_INFO( "connectivity.drivers","column type: " << aDBFColumn.db_typ);
 
         switch (aDBFColumn.db_typ)