net: hsr: Pass lockdep expression to RCU lists

node_db is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of hsr->list_lock.

Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.

Signed-off-by: Amol Grover <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/hsr/hsr_framereg.c

···
 		new_node->seq_out[i] = seq_out;
 
 	spin_lock_bh(&hsr->list_lock);
-	list_for_each_entry_rcu(node, node_db, mac_list) {
+	list_for_each_entry_rcu(node, node_db, mac_list,
+				lockdep_is_held(&hsr->list_lock)) {
 		if (ether_addr_equal(node->macaddress_A, addr))
 			goto out;
 		if (ether_addr_equal(node->macaddress_B, addr))