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/cnic.h b/drivers/net/cnic.h
index b328f6c..4456260 100644
--- a/drivers/net/cnic.h
+++ b/drivers/net/cnic.h
@@ -220,7 +220,7 @@
 #define ULP_F_INIT	0
 #define ULP_F_START	1
 #define ULP_F_CALL_PENDING	2
-	struct cnic_ulp_ops *ulp_ops[MAX_CNIC_ULP_TYPE];
+	struct cnic_ulp_ops __rcu *ulp_ops[MAX_CNIC_ULP_TYPE];
 
 	unsigned long cnic_local_flags;
 #define	CNIC_LCL_FL_KWQ_INIT		0x0