net: napi_hash_add() is no longer exported

There are no more users except from net/core/dev.c
napi_hash_add() can now be static.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index c9837fa..7385c1a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5017,7 +5017,7 @@ EXPORT_SYMBOL(sk_busy_loop);
 
 #endif /* CONFIG_NET_RX_BUSY_POLL */
 
-void napi_hash_add(struct napi_struct *napi)
+static void napi_hash_add(struct napi_struct *napi)
 {
 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state) ||
 	    test_and_set_bit(NAPI_STATE_HASHED, &napi->state))
@@ -5037,7 +5037,6 @@ void napi_hash_add(struct napi_struct *napi)
 
 	spin_unlock(&napi_hash_lock);
 }
-EXPORT_SYMBOL_GPL(napi_hash_add);
 
 /* Warning : caller is responsible to make sure rcu grace period
  * is respected before freeing memory containing @napi