net: rename CONFIG_NET_LL_RX_POLL to CONFIG_NET_RX_BUSY_POLL

Eliezer renames several *ll_poll to *busy_poll, but forgets
CONFIG_NET_LL_RX_POLL, so in case of confusion, rename it too.

Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0741a1e..9a41568 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -973,7 +973,7 @@
 						     gfp_t gfp);
 	void			(*ndo_netpoll_cleanup)(struct net_device *dev);
 #endif
-#ifdef CONFIG_NET_LL_RX_POLL
+#ifdef CONFIG_NET_RX_BUSY_POLL
 	int			(*ndo_busy_poll)(struct napi_struct *dev);
 #endif
 	int			(*ndo_set_vf_mac)(struct net_device *dev,