net: netrom: Add missing annotation for nr_node_stop()

Sparse reports a warning at nr_node_stop()
warning: context imbalance in nr_node_stop() - wrong count at exit
The root cause is the missing annotation at nr_node_stop()
Add the missing __releases(&nr_node_list_lock) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netrom/nr_route.c

@@ -850,6 +850,7 @@ static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
 }
 
 static void nr_node_stop(struct seq_file *seq, void *v)
+	__releases(&nr_node_list_lock)
 {
 	spin_unlock_bh(&nr_node_list_lock);
 }