SUNRPC: rpc_restart_call/rpc_restart_call_prepare should clear task->tk_status

When restarting an rpc call, we should not be carrying over data from the
previous call.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

net/sunrpc/clnt.c

@@ -1363,6 +1363,7 @@ rpc_restart_call_prepare(struct rpc_task *task)
 	if (RPC_ASSASSINATED(task))
 		return 0;
 	task->tk_action = call_start;
+	task->tk_status = 0;
 	if (task->tk_ops->rpc_call_prepare != NULL)
 		task->tk_action = rpc_prepare_task;
 	return 1;
@@ -1379,6 +1380,7 @@ rpc_restart_call(struct rpc_task *task)
 	if (RPC_ASSASSINATED(task))
 		return 0;
 	task->tk_action = call_start;
+	task->tk_status = 0;
 	return 1;
 }
 EXPORT_SYMBOL_GPL(rpc_restart_call);