oci8po: prevent segfault on php7
oci8po: prevent segfault on php7

The OCIFetchinto function is causing segfaults on php7 - probably
because the fields array is not initialised or it is optimised out. This
fixes just changes to use the safer function oci_fetch_array instead.

Fixes #259

Signed-off-by: Damien Regad <d9b599957bd54c22143053c16557076ca2185dbd@mantisbt.org>

ipso/ADOdb,ipso/ADOdb