Documentation: fix hotplug example

* add a missing call to libusb_handle_events_completed()
* add a missing argument to libusb_hotplug_deregister_callback()

libusb/hotplug.c

@@ -86,6 +86,10 @@
  *
  * The following code provides an example of the usage of the hotplug interface:
 \code
+#include <stdio.h>
+#include <stdlib.h>
+#include <libusb.h>
+
 static int count = 0;
 
 int hotplug_callback(struct libusb_context *ctx, struct libusb_device *dev,
@@ -131,10 +135,11 @@ int main (void) {
   }
 
   while (count < 2) {
+    libusb_handle_events_completed(NULL, NULL);
     usleep(10000);
   }
 
-  libusb_hotplug_deregister_callback(handle);
+  libusb_hotplug_deregister_callback(NULL, handle);
   libusb_exit(NULL);
 
   return 0;

libusb/version_nano.h

@@ -1 +1 @@
-#define LIBUSB_NANO 10867
+#define LIBUSB_NANO 10868