sunrpc: suppress page allocation warnings in xprt_alloc_slot()

It's easily possible for these allocations to fail since we're using
GFP_NOWAIT here. We don't want to spam the logs with warnings about
that though.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/xprt.c

@@ -979,7 +979,7 @@ static void xprt_alloc_slot(struct rpc_task *task)
 		list_del(&req->rq_list);
 		goto out_init_req;
 	}
-	req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT);
+	req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN);
 	if (!IS_ERR(req))
 		goto out_init_req;
 	switch (PTR_ERR(req)) {