staging: hv: fix a kernel warning in netvsc_linkstatus_callback()

netif_notify_peers() caused a kernel warning in netvsc_linkstatus_callback(),
because netvsc_linkstatus_callback() is within IRQ context. So we move
the first call to netif_notify_peers() into queued work as well, but with
zero delay.

In addition to "staging-next", this should also be back-ported to stable
kernels 2.6.32 and later.
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/netvsc_drv.c

@@ -214,8 +214,8 @@ void netvsc_linkstatus_callback(struct hv_device *device_obj,
 	if (status == 1) {
 		netif_carrier_on(net);
 		netif_wake_queue(net);
-		netif_notify_peers(net);
 		ndev_ctx = netdev_priv(net);
+		schedule_delayed_work(&ndev_ctx->dwork, 0);
 		schedule_delayed_work(&ndev_ctx->dwork, msecs_to_jiffies(20));
 	} else {
 		netif_carrier_off(net);