bonding: fix rx_handler locking

This prevents possible race between bond_enslave and bond_handle_frame
as reported by Nicolas by moving rx_handler register/unregister.
slave->bond is added to hold pointer to master bonding sructure. That
way dev->master is no longer used in bond_handler_frame.
Also, this removes "BUG: scheduling while atomic" message

Reported-by: Nicolas de Pesloüan <nicolas.2p.debian@gmail.com>
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Tested-by: Nicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 6b26962..90736cb 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -187,6 +187,7 @@
 	struct net_device *dev; /* first - useful for panic debug */
 	struct slave *next;
 	struct slave *prev;
+	struct bonding *bond; /* our master */
 	int    delay;
 	unsigned long jiffies;
 	unsigned long last_arp_rx;