sanity 27q hang on local testing.

I think this bug was introduced by LU-325, which changes the ENOSPC condition in handle_async_create() from OSCC_FLAG_NOSPC to OSCC_FLAG_NOSPC_BLK, however, the OSCC_FLAG_NOSPC_BLK never been set on client, because server wrongly processed the oa->o_valid: filter_precreate() set OBD_MD_FLFLAGS & OBD_FL_NOSPC_BLK on ENOSPC, however, the OBD_MD_FLFLAGS is reset as "OBD_MD_FLID | OBD_MD_FLGROUP" in filter_handle_precreate().

The end result is that the create process will never been wakeup when OSTs running of space.