net: mark netdev_create_hash __net_init

netdev_create_hash() is only called from netdev_init() which is marked
__net_init.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -6088,7 +6088,7 @@ netdev_features_t netdev_increment_features(netdev_features_t all,
 }
 EXPORT_SYMBOL(netdev_increment_features);
 
-static struct hlist_head *netdev_create_hash(void)
+static struct hlist_head * __net_init netdev_create_hash(void)
 {
 	int i;
 	struct hlist_head *hash;