drivers/net: remove some rcu sparse warnings

Add missing __rcu annotations and helpers.
minor : Fix some rcu_dereference() calls in macvtap

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index f459fb2..0132ea9 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -6759,7 +6759,7 @@
 	u32		tx_wake_thresh;
 
 #ifdef BCM_CNIC
-	struct cnic_ops		*cnic_ops;
+	struct cnic_ops	__rcu	*cnic_ops;
 	void			*cnic_data;
 #endif