staging: lustre: ptlrpc: request gets stuck in UNREGISTERING phase

Exit condition from UNREGISTERING phase is releasing of
both reply and bulk buffers.

Call ptlrpc_unregister_bulk() if ptlrpc_unregister_reply()
wasn't completed in async mode before switching to
UNREGISTERING phase.

Signed-off-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5259
Xyratex-bug-id: MRP-1960
Reviewed-on: http://review.whamcloud.com/10846


Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Ann Koehler <amk@cray.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>