Bluetooth: Convert L2CAP ident spinlock into a mutex

The spinlock protecting the L2CAP ident number can be converted into
a mutex since the whole processing is run in a workqueue. So instead
of using a spinlock, just use a mutex here.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 0c3c493..8538cb0 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -798,14 +798,14 @@
 	 *  200 - 254 are used by utilities like l2ping, etc.
 	 */
 
-	spin_lock(&conn->lock);
+	mutex_lock(&conn->ident_lock);
 
 	if (++conn->tx_ident > 128)
 		conn->tx_ident = 1;
 
 	id = conn->tx_ident;
 
-	spin_unlock(&conn->lock);
+	mutex_unlock(&conn->ident_lock);
 
 	return id;
 }
@@ -7016,7 +7016,7 @@
 		conn->hs_enabled = test_bit(HCI_HS_ENABLED,
 					    &hcon->hdev->dev_flags);
 
-	spin_lock_init(&conn->lock);
+	mutex_init(&conn->ident_lock);
 	mutex_init(&conn->chan_lock);
 
 	INIT_LIST_HEAD(&conn->chan_l);