staging/lustre/fids: fix compilation error with gcc 4.7.2

initialize oi.oi.oi_id which gcc 4.7.2 is afraid of being
used later.

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3179
Lustre-change: http://review.whamcloud.com/6064Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/include/lustre_fid.h

@@ -624,6 +624,7 @@ static inline void ost_fid_build_resid(const struct lu_fid *fid,
 {
 	if (fid_is_mdt0(fid) || fid_is_idif(fid)) {
 		struct ost_id oi;
+		oi.oi.oi_id = 0; /* gcc 4.7.2 complains otherwise */
 		if (fid_to_ostid(fid, &oi) != 0)
 			return;
 		ostid_build_res_name(&oi, resname);