Bluetooth: 6lowpan: Fix module refcount

This patch removes the additional module_put() in disconnect_all_peers()
making a correct module refcount so that the module can be removed after
disabling 6lowpan through debugfs.

Signed-off-by: Lukasz Duda <lukasz.duda@nordicsemi.no>
Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/6lowpan.c

@@ -1208,8 +1208,6 @@ static void disconnect_all_peers(void)
 
 		list_del_rcu(&peer->list);
 		kfree_rcu(peer, rcu);
-
-		module_put(THIS_MODULE);
 	}
 	spin_unlock(&devices_lock);
 }