- in llite and liblustre ll_prepare_md_op_data() zeroes out passed @op_data to avoid...

- in llite and liblustre ll_prepare_md_op_data() zeroes out passed @op_data to avoid garbage in it in caases caller did not zero it out. All fid allocations saved in op_data->fid2 are done after ll_prepare_md_op_data();

- in lmv replace all on stac allocations of struct md_op_data by memory allocated ones;
- in lmv fixed few memory leaks, cleanups.