connector: make callback argument type explicit

The connector documentation states that the argument to the callback
function is always a pointer to a struct cn_msg, but rather than encode it
in the API itself, it uses a void pointer everywhere.  This doesn't make
much sense to encode the pointer in documentation as it prevents proper C
type checking from occurring and can easily allow people to use the wrong
pointer type.  So convert the argument type to an explicit struct cn_msg
pointer.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/connector/cn_queue.c b/drivers/connector/cn_queue.c
index c769ef2..d478aef 100644
--- a/drivers/connector/cn_queue.c
+++ b/drivers/connector/cn_queue.c
@@ -87,7 +87,9 @@
 	kfree(d->free);
 }
 
-static struct cn_callback_entry *cn_queue_alloc_callback_entry(char *name, struct cb_id *id, void (*callback)(void *))
+static struct cn_callback_entry *
+cn_queue_alloc_callback_entry(char *name, struct cb_id *id,
+			      void (*callback)(struct cn_msg *))
 {
 	struct cn_callback_entry *cbq;
 
@@ -120,7 +122,8 @@
 	return ((i1->idx == i2->idx) && (i1->val == i2->val));
 }
 
-int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id, void (*callback)(void *))
+int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id,
+			  void (*callback)(struct cn_msg *))
 {
 	struct cn_callback_entry *cbq, *__cbq;
 	int found = 0;