fix the problem of mds_open_by_fid() being panic in interoperability case
b=19607
i=johann
j=alexander.zarochentsev
(lustre_msg_get_transno(req->rq_reqmsg) >
req->rq_export->exp_last_committed) &&
(rec->ur_flags & MDS_OPEN_CREAT) &&
- pre_versions[0] != 0) {
+ (pre_versions && pre_versions[0] != 0)) {
/* need parent to set version */
dparent = mds_fid2dentry(mds, rec->ur_fid1, NULL);
if (IS_ERR(dparent)) {