net: do not initialise statics to 0

This patch fixes the checkpatch.pl error to dev.c:

ERROR: do not initialise statics to 0
Signed-off-by: NWei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -2422,7 +2422,7 @@ EXPORT_SYMBOL(__skb_tx_hash);
 
 static void skb_warn_bad_offload(const struct sk_buff *skb)
 {
-	static const netdev_features_t null_features = 0;
+	static const netdev_features_t null_features;
 	struct net_device *dev = skb->dev;
 	const char *name = "";