Phonet: convert devices list to RCU

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/phonet/pn_dev.h b/include/net/phonet/pn_dev.h
index afa7def..d7b989c 100644
--- a/include/net/phonet/pn_dev.h
+++ b/include/net/phonet/pn_dev.h
@@ -25,7 +25,7 @@
 
 struct phonet_device_list {
 	struct list_head list;
-	spinlock_t lock;
+	struct mutex lock;
 };
 
 struct phonet_device_list *phonet_device_list(struct net *net);