Fix --usb-dump when reinit_usb() is called

cgminer.c

@@ -9621,9 +9621,11 @@ static void reinit_usb(void)
 
 	applog(LOG_DEBUG, "Reinitialising libusb");
 	libusb_exit(NULL);
+	cgusb_uninitialize();
 	err = libusb_init(NULL);
 	if (err)
 		quit(1, "Reinit of libusb failed err %d:%s", err, libusb_error_name(err));
+	cgusb_check_init();
 	usb_reinit = false;
 }
 

usbutils.c

@@ -1484,7 +1484,12 @@ void usb_all(int level)
 	libusb_free_device_list(list, 1);
 }
 
-static void cgusb_check_init()
+void cgusb_uninitialize()
+{
+	stats_initialised = false;
+}
+
+void cgusb_check_init()
 {
 	mutex_lock(&cgusb_lock);
 

usbutils.h

@@ -487,6 +487,8 @@ struct cgpu_info;
 bool async_usb_transfers(void);
 void cancel_usb_transfers(void);
 void usb_all(int level);
+void cgusb_check_init();
+void cgusb_uninitialize();
 void usb_list(void);
 const char *usb_cmdname(enum usb_cmds cmd);
 void usb_applog(struct cgpu_info *cgpu, enum usb_cmds cmd, char *msg, int amount, int err);